JP3635889B2 - Flow-through type device, electrochemiluminescence immunoassay device - Google Patents

Description

図４（Ａ）、図４（Ｂ）、図４（Ｃ）は各々、音響波の周波数が、ｆ（ｔ）＝１．０ＭＨｚ、１．４ＭＨｚ、０．６ＭＨｚである各時点に於ける定在波を横波表示で示す図である。図４（Ａ）、図４（Ｂ）、図４（Ｃ）に於いて、各時点に於ける定在波の節の間隔を、ｄ₁（４１１）、ｄ₂（４２１）、ｄ₃（４３１）、溶液中の音速を約１５００ｍ／ｓｅｃとすると、ｄ₁≒０．７５ｍｍ、ｄ₂≒０．５４ｍｍ、ｄ₃≒１．２５ｍｍである。なお電気音響変換器１５、１６は、距離Ｄを保ち平行に配置されている。
【００２２】
図４（Ａ）、図４（Ｂ）、図４（Ｃ）に於いて、電気音響変換器１５による音響波の伝達時間と、電気音響変換器１６による音響波の伝達時間とが等しくなる面を点線４１２、４２２、４３２により示す。点線４１２、４２２、４３２により示される面を、以下の説明では簡単のために、「定在波中間面」と表わす。なお電気音響変換器１５、１６による音響波の伝達経路が音響的に等価である時には、定在波中間面は、図１に示す電気音響変換器１５、１６から各々等しい距離にある面となる。
【００２３】
以下、音響波の周波数を変化させた時の定在波の節の動きを、図４（Ａ）、図４（Ｂ）、図４（Ｃ）により説明する。定在波中間面のすぐ左側の定在波の節（以下、「左第１節」と表わす）と、定在波中間面の右側の２つ目の定在波の節（以下「右第２節」と表わす）を例にとって説明する。
【００２４】
図３（Ａ）に示す時点（ａ）では、音響波の周波数が、ｆ（ｔ）＝１．０ＭＨｚであり、左第１節に捕捉される気泡の位置は図４（Ａ）に示すｘ方向の位置４１３である。図３（Ａ）に示す時点（ａ）と時点（ｂ）の間では、音響波の周波数が高い方向に変化して、時点（ｂ）で、ｆ（ｔ）＝１．４ＭＨｚに到達すると、気泡は図４（Ｂ）に示すｘ方向の位置４２３まで移動する。次いで、図３（Ａ）に示す時点（ｂ）と時点（ｃ）の間では、音響波の周波数が低い方向に変化して、時点（ｃ）で、ｆ（ｔ）＝１．０ＭＨｚに到達すると、気泡は図４（Ａ）に示すｘ方向の位置４１３に戻る。図３（Ａ）に示す時点（ｃ）と時点（ｄ）の間では、音響波の周波数が更に低い方向に変化して、時点（ｄ）で、ｆ（ｔ）＝０．６ＭＨｚに到達すると、気泡は図４（Ｃ）に示すｘ方向の位置４３３まで移動する。
【００２５】
更に、図３（Ａ）に示す時点（ｄ）と時点（ｅ）の間では、音響波の周波数が再び高い方向に変化して、時点（ｅ）で、ｆ（ｔ）＝１．０ＭＨｚに到達すると、気泡はｘ方向の位置４１３に戻る。この様に、図３（Ａ）に示す音響波の周波数変調により、左第１節に捕捉される気泡の移動範囲は、図４（Ｄ）に示す様に、周期Ｔ（０．２５ｓｅｃ）毎にｘ方向の範囲４４３を移動し、作用電極１１の表面の範囲４４３にある物質に力を及ぼす（作用する）。
【００２６】
図３（Ａ）に示す時点（ａ）では、音響波の周波数が、ｆ（ｔ）＝１．０ＭＨｚであり、右第２節に捕捉される気泡の位置は図４（Ａ）に示すｘ方向の位置４１４である。図３（Ａ）に示す時点（ａ）と時点（ｂ）の間では、音響波の周波数が高い方向に変化して、時点（ｂ）で、ｆ（ｔ）＝１．４ＭＨｚに到達すると、気泡は図４（Ｂ）に示すｘ方向の位置４２４まで移動する。次いで、図３（Ａ）に示す時点（ｂ）と時点（ｃ）の間では、音響波の周波数が低い方向に変化して、時点（ｃ）で、ｆ（ｔ）＝１．０ＭＨｚに到達し、気泡は図４（Ａ）に示すｘ方向の位置４１４を経由して、フローセル流路の壁面（１１２−２）に到達する。
【００２７】
図３（Ａ）に示す時点（ｃ）と時点（ｄ）の間では、音響波の周波数が低い方向に変化して、気泡がフローセル流路のｘ方向の壁面（１１２−２）に到達した後、更に音響波の周波数が低い方向に変化すると、定在波の節はフローセル流路の外部に出るのでこの定在波の節に捕捉されていた気泡は拡散してしまう。時点（ｄ）で、ｆ（ｔ）＝０．６ＭＨｚに到達した後、図３（Ａ）に示す時点（ｄ）と時点（ｅ）の間で、定在波の節が再びフローセル流路に戻り、新たな気泡が捕捉される。この様に、図３（Ａ）に示す音響波の周波数変調により、右第２節に捕捉される気泡の移動範囲は、図４（Ｄ）に示す様に、周期Ｔ（０．２５ｓｅｃ）毎にｘ方向の範囲４４４を移動し、作用電極１１の表面の範囲４４４にある物質に力を及ぼす（作用する）。
【００２８】
以上説明した様に本実施例では、定在波の節（左第１節、右第２節）とこれらに捕捉された気泡は、ｘ方向の範囲４４３、４４４を１秒間に（１／Ｔ）回だけ往復移動し、作用電極１１の表面の範囲４４３、４４４に存在する物質を押し流す。周波数変調法では、定在波中間面の位置が重要である。音響波の周波数が増加する場合は、音響波の定在波の節の位置（気泡が捕捉される位置）は、常に定在波中間面に近づく方向に移動する。また、音響波の周波数が減少する場合は、音響波の定在波の節の位置（気泡が捕捉される位置）は、常に定在波中間面より離れる方向に移動する。
【００２９】
（第４の実施例）
図５は、「周波数変調法」による音響波の定在波の節の位置（気泡が捕捉される位置）の変化を説明する図である。第３の実施例では、音響波の周波数を正弦的に変化させたが、本実施例では、（数３）に於ける周波数ｆ₀を、（数６）〜（数８）で示す周期関数ｆ（ｔ）で置き換え、電気音響変換器１６、１５を（数１１）に示す周波数変調した交流電圧波形により駆動する。
【００３０】
【数６】
ｆ（ｔ）＝ｆ_min＋（ｆ_max−ｆ_min）（ｔ／Ｔ） …（数６）
但し、（数６）の周期関数ｆ（ｔ）は周期Ｔを持ち、（数７）〜（数８）を満たし、ｔ＝ｎＴとｔ＝（ｎ＋１）Ｔとの間（ｎ＝０、１、２、…）でｆ（ｔ）は直線的に単調増加する。（数４）に於ける周波数ｆ₀、Δｆ、とｆ_min、ｆ_maxとの関係は、（数９）〜（数１０）である。
【００３１】
【数７】
ｆ（ｔ＝ｎＴ；ｎ＝０、１、２、…）＝ｆ_min（起点周波数） …（数７）
【００３２】
【数８】
ｆ（ｔ→ｎＴ；ｎ＝０、１、２、…）→ｆ_max（終点周波数） …（数８）
【００３３】
【数９】
２ｆ₀＝（ｆ_min＋ｆ_max） …（数９）
【００３４】
【数１０】
２Δｆ＝（ｆ_max−ｆ_min） …（数１０）
【００３５】
【数１１】

図５（Ａ）は、音響波の周波数を（数６）〜（数８）で示す周期関数ｆ（ｔ）、即ち、起点周波数ｆ_minから終点周波数ｆ_maxまで、直線的に単調増加で繰り返し変化させる周波数変調の例を示す。図５（Ａ）に於いて、周期Ｔ＝０．２５ｓｅｃ（４Ｈｚ）、ｆ_min＝０．６ＭＨｚ、ｆ_max＝１．４ＭＨｚ、ｆ₀＝１ＭＨｚ、Δｆ＝０．４ＭＨｚである。図５（Ｂ）に示す矢印は、図５（Ａ）に示す様に、音響波の周波数を直線的に周期的に変化させた時の音響波の定在波の節の位置の変化を示す。図５（Ｂ）に示す様に、音響波の定在波の節の位置は周期的に変化し、→４１４→４２４→、４３３→４１３→４２３→のように移動する。
【００３６】
図５（Ａ）に示す、時点（ａ）、（ｂ）、（ｃ）の各々に於ける音響波の周波数は、図３（Ａ）に示す、時点（ｄ）、（ａ）、（ｂ）の各々に於ける音響波の周波数に等しい。図５（Ａ）に示す、時点（ａ）、（ｂ）、（ｃ）に於ける定在波の状態は、各々、図４（Ｃ）、図４（Ａ）、図４（Ｂ）と同一である。但し、図５（Ａ）の時点（ｃ）は、直ちに時点（ｄ）に移り、対応して定在波の状態も、図４（Ｂ）の状態から図４（Ｃ）の状態に戻る。
【００３７】
本実施例では、第３の実施例と同様に、定在波の節（左第１節、右第２節）に捕捉された気泡は、図４（Ｄ）で示した移動範囲４４３、４４４を、定在波中間面に向かって繰り返し移動する。本実施例では、ｆ_min（起点周波数）＜ｆ_max（終点周波数）の時、定在波の節は常に定在波中間面へ向かって移動し、逆に、ｆ_min（起点周波数）＞ｆ_max（終点周波数）の時、定在波の節は、常に定在波中間面より離れる方向に移動する。即ち、本実施例では、定在波中間面の位置がフローセルの流れの中心部に来る様に調節し、ｆ_min（起点周波数）＜ｆ_max（終点周波数）として、作用電極１１の表面の物質を常にフローセルの流れの中心部へ集める様に制御できる。
【００３８】
（第５の実施例）
図６は、「周波数変調法の改良法」により定在波の節の空間的分布を任意に変化させることを説明する図であり、図２（Ａ）に示す点線２１に於ける作用電極１１の表面に垂直な断面図である。第３の実施例では、（数５）に示す周波数変調した交流電圧波形により、同一の位相で電気音響変換器１６、１５を駆動したので、２つの音響波の位相が一致しており、定在波中間面は常に振幅が最大な部分である。例えば、第３の実施例に示す周波数変調法の改良として、（数１２）〜（数１３）に示す周波数変調した交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）の位相α₁、α₂に位相差を（α₂−α₁）を持たせ、音響波の定在波の節の空間的分布を任意に変更できる。
【００３９】
【数１２】

【００４０】
【数１３】

例えば、図６（Ａ）に示す様に、電気音響変換器１５を駆動する周波数変調した交流電圧波形Ｖ₂（ｔ）の位相α₂と、電気音響変換器１６を駆動する周波数変調した交流電圧波形Ｖ₁（ｔ）の位相α₁の差（位相差）を（数１４）とする時、定在波の節は、電気音響変換器１５から離れる方向（図６（Ａ）ではｘ軸の負の方向）へ、音響波の波長のβ／４に等しい距離だけ移動する。点線６１は位相差が無い場合（β＝０）の音響波の定在波の節の位置を示し、点線６２は位相差が有る場合（β≠０）の音響波の定在波の節の位置を示し、音響波の定在波の節の位置は移動距離６３だけ移動する。
【００４１】
【数１４】

更に、（数１４）に於いてβ＝１として、図６（Ｂ）に示す様に、位相差をπとして、即ち、位相α₂を位相α₁に対して、πだけ進ます場合、定在波の節は電気音響変換器１５から離れる方向（図６（Ｂ）ではｘ軸の負の方向）へ、音響波の波長の１／４に等しい距離だけ移動するので、定在波中間面６４を常に定在波の節とする様に変更できる。本実施例の方法では、音響波の定在波の節の位置（気泡が捕捉される位置）を任意に調節可能である。
【００４２】
（第６の実施例）
図７は、「位相変調法」による音響波の定在波の節の位置（気泡が捕捉される位置）の変化を説明する図であり、図２（Ａ）に示す点線２１に於ける作用電極１１の表面に垂直な断面図である。本実施例では、電気音響変換器１６、１５を、（数１５）〜（数１６）に示す周波数変調した交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）の位相α₁、α₂の差（位相差（α₂−α₁））を時間変化させる位相変調法により駆動させて、音響波の定在波の節の位置を変化させる。
【００４３】
【数１５】
Ｖ₁（ｔ）＝Ｖ₀ｓｉｎ｛２πｆ₀ｔ＋α₁（ｔ）｝ …（数１５）
【００４４】
【数１６】
Ｖ₂（ｔ）＝Ｖ₀ｓｉｎ｛２πｆ₀ｔ＋α₂（ｔ）｝ …（数１６）
例えば、図７（Ａ）の電気音響変換器１６に対する交流電圧波形Ｖ₁（ｔ）の位相α₁（ｔ）と電気音響変換器１５に対する交流電圧波形Ｖ₂（ｔ）の位相α₂（ｔ）との差、｛α₂（ｔ）−α₁（ｔ）｝（位相差）を（数１７）に従って時間変化させる。
【００４５】
【数１７】
α₂（ｔ）−α₁（ｔ）＝２πｔ／Ｔ …（数１７）
図７（Ｂ）は、Ｔ＝０．３７５ｓｅｃ（２．７Ｈｚ）の時の、位相差｛α₂（ｔ）−α₁（ｔ）｝の時間変化、及び音響波の定在波の節の位置の変化量を示す。位相差｛α₂（ｔ）−α₁（ｔ）｝と音響波の定在波の節の位置の変化量ｈ（ｔ）とは、（数１８）に示す比例関係があるため、各時点での音響波の定在波の節の位置は、図７（Ｂ）の右縦軸の値となる。なおｄは、図７（Ａ）に示す様に、定在波の節の間の距離である。定在波の節は、図７（Ａ）に示す矢印７１の方向に速度ｄ／Ｔで等速運動する。位相差２πは、位相差ゼロと物理的に等しく、本実施例での音響波の定在波の節の位置の変化は、周期Ｔで繰り返す。
【００４６】
【数１８】
ｈ（ｔ）＝｛α₂（ｔ）−α₁（ｔ）｝ｄ／（２π）＝（ｔ／Ｔ）ｄ…（数１８）
本実施例では、音響波の周波数ｆ₀を時間変化させずに、音響波の定在波の節の位置を変化させ、音響波の定在波の節の位置（気泡が捕捉される位置）を広い範囲で移動させるため、作用電極１１の表面を洗浄する作用を持つ気泡を広い範囲で移動可能であり、作用電極１１の表面全体を洗浄する場合に効果的である。
【００４７】
（第７の実施例）
本実施例では、電気音響変換器１６、１５を駆動する交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）の周波数を微少量ずらして音響波を発生し、フローセル流路を照射する「うなり法」により、音響波の定在波の節を１方向に移動させる。電気音響変換器１６、１５を駆動する交流電圧波形を、（数１）〜（数２）に於いて、Ｖ₀₁＝Ｖ₀₂＝Ｖ₀、ｆ₁＝ｆ₀、ｆ₂＝ｆ₀＋δｆ、α₁＝α₂＝αとして、（数１９）〜（数２０）とする。例えば、ｆ₁＝ｆ₀＝１ＭＨｚ、δｆ＝２Ｈｚとして、電気音響変換器１６、１５を各々振動させる。
【００４８】
【数１９】
Ｖ₁（ｔ）＝Ｖ₀ｓｉｎ（２πｆ₀ｔ＋α） …（数１９）
【００４９】
【数２０】
Ｖ₂（ｔ）＝Ｖ₀ｓｉｎ｛２π（ｆ₀＋δｆ）ｔ＋α｝ …（数２０）
この時、電気音響変換器１５と１６の間の空間には、周波数１ＭＨｚの音響波により生じる定在波とほぼ同等の定在波が形成され、且つその定在波の腹、及び節は、相対的に周波数の高い周波数で駆動されている電気音響変換器（上の例では電気音響変換器１５）の方向へ移動速度ｖで移動する。定在波の腹、及び節の移動速度ｖは、λ_mを電気音響変換器１６、１５から発する各音響波の液相での波長の平均値として、（数２１）により与えられ、本実施例ではδｆ＝２Ｈｚであり、液相での音速を１５００ｍ／ｓｅｃとすると、λ_m≒１．５ｍｍであり、ｖ≒３．０ｍｍ／ｓｅｃとなる。
【００５０】
【数２１】
ｖ＝δｆλ_m …（数２１）
本実施例では、定在波の節を１方向に移動可能であり、作用電極１１の表面を洗浄する作用を持つ気泡を１方向に移動可能となり、作用電極１１の表面全体を洗浄する場合に効果的である。
【００５１】（第８の実施例）以上の各実施例で説明した周波数変調法、位相変調法、うなり法を使用して、周波数変調法と位相変調法との組合わせ、周波数変調法とうなり法との組合わせも可能である。
【００５２】
図８は、第４の実施例で説明した「周波数変調法」と第７の実施例で説明した「うなり法」を組合わせた「組合わせ法」による、音響波の定在波の節の位置（気泡が捕捉される位置）の変化を説明する図である。電気音響変換器１６、１５を（数１１）と同様に周波数変調した、（数２９）〜（数３０）で示される交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）により駆動する。例えば、交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）の周波数ｆ₁（ｔ）、ｆ₂（ｔ）は、（数２２）〜（数２３）で示される。
【００５３】
【数２２】
ｆ₁（ｔ）＝ｆ_1min＋（ｆ_1max−ｆ_1min）（ｔ／Ｔ） …（数２２）
【００５４】
【数２３】
ｆ₂（ｔ）＝ｆ_2min＋（ｆ_2max−ｆ_2min）（ｔ／Ｔ） …（数２３）
但し、周期関数ｆ₁（ｔ）、ｆ₂（ｔ）は周期Ｔを持ち、（数２４）〜（数２７）を満たし、ｔ＝ｎＴとｔ＝（ｎ＋１）Ｔとの間（ｎ＝０、１、２、…）で、ｆ₁（ｔ）、ｆ₂（ｔ）は直線的に単調増加し、ｆ₂（ｔ）とｆ₁（ｔ）との差（δｆ’）が、常に一定である場合を考えると、差δｆ’は（数２８）で与えられる。
【００５５】
【数２４】
ｆ₁（ｔ＝ｎＴ；ｎ＝０、１、２、…）＝ｆ_1min（起点周波数） …（数２４）
【００５６】
【数２５】
ｆ₁（ｔ→ｎＴ；ｎ＝０、１、２、…）→ｆ_1max（終点周波数） …（数２５）
【００５７】
【数２６】
ｆ₂（ｔ＝ｎＴ；ｎ＝０、１、２、…）＝ｆ_2min（起点周波数） …（数２６）
【００５８】
【数２７】
ｆ₂（ｔ→ｎＴ；ｎ＝０、１、２、…）→ｆ_2max（終点周波数） …（数２７）
【００５９】
【数２８】

【００６０】
【数２９】

【００６１】
【数３０】

図８（Ａ）は、周波数ｆ₁（ｔ）の時間変化８２、周波数ｆ₂（ｔ）の時間変化８１、（数２８）で与えられる差δｆ’８３を示す。図８（Ｂ）は、ｆ₂（ｔ）とｆ₁（ｔ）との差（δｆ’）が常に一定として、電気音響変換器１６、１５を（数２９）〜（数３０）で示される交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）により駆動する時の、音響波の節の移動の状態を示す図である。図８（Ｂ）の縦軸は、電気音響変換器１６と１５とを結ぶｘ軸に投影した音響波の定在波の節の位置を示し、電気音響変換器１６の位置が原点である。点線８４は定在波中間面を示す。
【００６２】
点線８５、点線８６は各々、（数３１）〜（数３２）で与えられる起点周波数の平均周波数ｆ_Amin、終点周波数の平均周波数ｆ_Amaxである場合の「うなり法」での音響波の定在波の節の移動経路を示す。
【００６３】
【数３１】
ｆ_Amin＝（ｆ_1min＋ｆ_2min） …（数３１）
【００６４】
【数３２】
ｆ_Amax＝（ｆ_1max＋ｆ_2max） …（数３２）
定在波の節は、第４の実施例で説明した周波数の変化と共に移動するモードと、第７の実施例で説明した「うなり」により移動するモードが合成され、点線８５と点線８６で囲まれる範囲を、矢印で示す様に移動する。本実施例では、気泡の移動する範囲を、「周波数変調法」と「うなり法」とにより変化させ、作用電極１１の表面を広範囲に洗浄できる。
【００６５】
（第９の実施例）
以上の実施例では、電気音響変換器１６、１５を、（数１）〜（数２）で示す交流電圧波形Ｖ₁（ｔ）、Ｖ₂（ｔ）で駆動する例を説明したが、電気音響変換器１６、１５を、（数３３）〜（数３４）に示す矩形波ｇを使用して駆動することもできる。
【００６６】
【数３３】
Ｖ₁（ｔ）＝Ｖ₀₁ｇ（２πｆ₁ｔ＋α₁） …（数３３）
【００６７】
【数３４】
Ｖ₂（ｔ）＝Ｖ₀₂ｇ（２πｆ₂ｔ＋α₂） …（数３４）
但し、ｎ＝０、１、２、…、ｆを周波数、τを周期として矩形波ｇを（数３５）の様に定義する。
【００６８】
図９は、電気音響変換器を駆動する矩形波ｇを示す図である。
【００６９】
【数３５】

第２の実施例と同様に、電気音響変換器１６、１５を駆動する電圧波形を、（数３３）〜（数３４）に於いて、Ｖ₀₁＝Ｖ₀₂＝Ｖ₀、ｆ₁＝ｆ₂＝ｆ₀、α₁＝α₂＝αとして、（数３６）としさらに、ｆ₀に（数４）のｆ（ｔ）を代入した（数３７）として、第３の実施例の「周波数変調法」により音響波の定在波の節の位置の変化させることができる。例えば、Ｖ₀、ｆ₀を、Ｖ₀＝１５０Ｖ、ｆ₀＝１ＭＨｚとする。
【００７０】
【数３６】
Ｖ₁（ｔ）＝Ｖ₂（ｔ）＝Ｖ₀ｇ（２πｆ₀ｔ＋α） …（数３６）
【００７１】
【数３７】

上記と同様にして、第４から第８の実施例における電気音響変換器１６、１５を駆動する電圧波形を矩形波ｇとすることができる。即ち、電気音響変換器１６、１５を駆動する電圧波形を矩形波ｇとして、第４の実施例の「周波数変調法」、第５の実施例の「周波数変調法の改良法」、第６の実施例の「位相変調法」、第７の実施例の「うなり法」、第８の実施例の「組合わせ法」の各方法により、音響波の定在波の節の位置（気泡が捕捉される位置）の変化させることができる。電気音響変換器１６、１５を駆動する電圧波形は、「周波数変調法」の場合は（数１１）を参照して（数３８）、「周波数変調法の改良法」の場合は（数１２）〜（数１４）を参照して（数３９）〜（数４１）、「位相変調法」の場合は（数１５）〜（数１７）を参照して（数４２）〜（数４４）、「うなり法」の場合は（数１９）〜（数２０）を参照して（数４５）〜（数４６）、「組合わせ法」の場合は（数２９）〜（数３０）を参照して（数４７）〜（数４８）、とする。
【００７２】
【数３８】

【００７３】
【数３９】
Ｖ₁（ｔ）＝Ｖ₀ｇ｛２π［ｆ₀＋Δｆｓｉｎ（２πｔ／Ｔ）］ｔ＋α₁）｝…（数３９）
【００７４】
【数４０】
Ｖ₂（ｔ）＝Ｖ₀ｇ｛２π［ｆ₀＋Δｆｓｉｎ（２πｔ／Ｔ）］ｔ＋α₂）｝…（数４０）
【００７５】
【数４１】
α₂−α₁＝βπ …（数４１）
【００７６】
【数４２】
Ｖ₁（ｔ）＝Ｖ₀ｇ｛２πｆ₀ｔ＋α₁（ｔ）｝ …（数４２）
【００７７】
【数４３】
Ｖ₂（ｔ）＝Ｖ₀ｇ｛２πｆ₀ｔ＋α₂（ｔ）｝ …（数４３）
【００７８】
【数４４】
α₂（ｔ）−α₁（ｔ）＝２πｔ／Ｔ …（数４４）
【００７９】
【数４５】
Ｖ₁（ｔ）＝Ｖ₀ｇ（２πｆ₀ｔ＋α） …（数４５）
【００８０】
【数４６】
Ｖ₂（ｔ）＝Ｖ₀ｇ｛２π（ｆ₀＋δｆ）ｔ＋α｝ …（数４６）
【００８１】
【数４７】

【００８２】
【数４８】

矩形波駆動は、２つの電位を周期的に切り替えて実現でき、電気音響変換器１６、１５を本実施例の各種変調法により矩形波駆動する場合、正弦波駆動と比較し単純な回路で実現できるという効果が有り、特に、（数３３）及び（数３４）で示す矩形波は、電圧Ｖ₀₁、Ｖ₀₂の電源、及びこれら電圧の印加と接地とを周期的に切り替えるスイッチング回路で実施でき、電気音響変換器を単純な回路構成により駆動できるという効果がある。
【００８３】
（第１０の実施例）
本発明では、フローセル内部の洗浄を効率良く実行するために、フロースルー型検出器のフローセル流路に音響波を効率よく照射する必要がある。
【００８４】
図１０は、本発明の第１０の実施例に於いて、フロースルー型検出器のフローセルの構成を示す図である。本実施例のフロースルー型検出器のフローセル流路は、所定の容積の内部空間を持ち溶液が流されるセル部３１６と、溶液の流入口３１１と排出口３１２を持つ上部板３１７から構成され、溶液が流入口３１１から流入され排出口３１２から排出され、セル部３１６の内部空間にフローセル流路が形成される。セル部３１６の壁の一部分が高分子ゴム３１３で構成され、高分子ゴム３１３の外面側に電気音響変換器３１４が配置され、セル部３１６の下部に磁性微粒子を保持する磁場を形成する磁石３１５が配置されている。電気音響変換器３１４として、例えば、ＰＺＴの圧電素子を使用する。
【００８５】
高分子ゴム３１３の部分は、セル部３１６の壁の一部分に取り外しが可能な構造とし、電気音響変換器３１４の交換を容易な構造とする。図１０に示す例では、電気音響変換器３１４を１個だけ使用しているが、複数個使用して、フローセル内部の洗浄を効率を高くしても良い。例えば、高分子ゴム３１３の部分をセル部３１６の対向する壁の一部分に取り外しが可能に配置し、各高分子ゴムに電気音響変換器を配置する。
【００８６】
電気音響変換器３１４による音響波の周波数は、高周波であるほど洗浄の効率が大きく、周波数１ＭＨｚ以上が好適である。電気音響変換器３１４により音響波が送波される方向で、高分子ゴム３１３は平行な２面を持つ。この２面間の距離、即ち、高分子ゴム３１３の厚さを音響波の波長の（１／４）の整数倍にして、フローセル内への音響波の照射の効率を大とするのが良い。
【００８７】
音響特性が水溶液と近似の音響特性を持つ高分子ゴム３１３を使用し、電気音響変換器による音響波を効率よくフローセル流路内に伝搬させる。即ち、高分子ゴム３１３の音速を約１５００ｍ／ｓｅｃ、音響インピーダンスを１．４〜１．６ＭＲｌａｙｓとし、音響減衰の小さい高分子ゴムを使用する。高分子ゴム３１３として、例えば、イソブチレンゴム（ＩＲ）、天然ゴム（ＮＲ）、スチレン・ブタジエンゴム（ＳＢＲ）、エチレン・プロピレン・ジエン共重合体（ＥＰＤＭ）、ブタジエンゴム（ＢＲ）が好ましく、音速が約１５５０ｍ／ｓｅｃ、音響インピーダンスが約１．５ＭＲｌａｙｓ、音響減衰が１．５ｄＢ／ｃｍ以下（３ＭＨｚに於いて）である。この他、シリコーンゴム（ＦＶＭＱ、ＭＱ、ＰＭＱ、ＰＶＭＱ、ＶＭＱ）、フッ素ゴム、ポリウレタンゴム、エピクロロヒドリンゴム、アクリルゴム等も使用できる。特にフッ素ゴム（６フッ化プロピレンとフッ化ビニリデンの共重合体）は薬品耐性が良く好適に使用できる。
【００８８】
図１０に示す構成では、電気音響変換器がフローセル流路に直接接していないため、電気音響変換器は、溶液による侵食、変性を受けず、電気音響変換器の振動の際に発生する熱がフローセル流路に伝搬しにくい等の特徴がある。
【００８９】
次に、本実施例のフロースルー型検出器の使用法について説明する。先ず、磁石３１５によりフローセル内に磁場を形成し、試料中の検査対象物質を捕捉した磁性微粒子を含む溶液を流入口３１１より導入すると、磁性微粒子はフローセル内の磁場の強い領域の壁面に保持される。次に、磁性微粒子に捕捉されている検査対象物質を検出して定量分析を行なう。この検出法として、例えば、ルテニウム錯体を標識として使用し電気化学発光反応による発光を検出する方法がある。
【００９０】
検査対象物質を検出して定量分析を行なった後、磁石３１５の磁場を消去する。磁場の消去は、磁石１５として電磁石を使用する時は電流を切り、永久磁石を使用する時はフローセル流路から永久磁石を遠ざけて行なう。磁場の消去の後、流入口３１１より洗浄溶液を流入すると共に電気音響変換器３１４による音響波をフローセル流路内に照射して、フローセル内を洗浄する。洗浄溶液は、例えば、水酸化カリウム等の強塩基溶液、次亜塩素酸水溶液が好適に使用できる。フローセル内の洗浄後、リン酸緩衝液等でコンディショニングを行ない、次の試料の測定に移行する。
【００９１】
（第１１の実施例）
図１１は、本発明の第１１の実施例に於いて、電気化学発光反応を利用するフロースルー型化学分析装置のフローセルを示す図である。フローセルは、白金の平板電極２１１を配置したＰＥＥＫ（Ｐｏｌｙ−Ｅｔｈｅｒ−Ｅｔｈｅｒ−Ｋｅｔｏｎｅ）製の下基板３２１と、流入口２２２と排出口２２３を持ち、白金の線電極２２１が配置されるアクリル製の上基板３２２と、フッ素ゴム平板を金型により打ち抜いてフローセル流路２３１の空間とＰＺＴが配置される空間とを形成したフッ素ゴムガスケット３２３とを、重ね合わせて構成される。フッ素ゴムガスケット３２３のＰＺＴが配置される空間に、ＰＺＴの圧電素子２４１、２４２が対向して設置されている。圧電素子の共振周波数は１ＭＨｚである。
【００９２】
電気化学発光標識の１つであるルテニウム錯体を結合した磁性微粒子と電気化学発光反応で使用する還元剤と試料と含む溶液をフローセルに導入し、磁性微粒子を平板電極２１１に磁石（図示せず）で保持し、線電極２２１と平板電極２１１に電圧を印加して電気化学発光反応を誘導し、その結果生じる発光強度をアクリル製の上基板３２２を介して測定した（測定結果をＳ₁とする）。次に、洗浄溶液として、０．１Ｎの水酸化カリウム水溶液を導入しながら、所定の電圧振幅をもち１ＭＨｚの正弦波を印加して圧電素子を駆動し音響波を発生させ、フローセル内の磁性微粒子を、洗浄時間を一定として、洗浄して除去した。
【００９３】
洗浄の後、電気化学発光で使用する還元剤のみを含む溶液をフローセルに導入し、再び、線電極２２１と平板電極２１１に電圧を印加して電気化学発光反応を誘導し、その結果生じる発光強度をアクリル製の上基板３２２を介して測定した（測定結果をＳ₂とする）。以上の実験の測定結果から、フローセルのキャリーオーバー（異なる試料の間の検体混入）Ｃ_OをＣ_O＝Ｓ₂／Ｓ₁により定義し、フッ素ゴムを介して音響波をフローセル内に照射する効果を評価した。対比実験は、全てに実験条件を同一として、フッ素ゴムガスケット３２３の代りに、フッ素ゴム平板と同じ厚さのＰＥＥＫ板を使用する構成のフローセルを使用してキャリーオーバーＣ_Oを求めた。
【００９４】
図１２は、キャリーオーバーＣ_OとＰＺＴの駆動電圧振幅（Ｖ_PP）との関係を示す図である。図１２に於いて、Ｖ_PP＝０の点は、ＰＺＴを駆動せず音響波をフローセル内に照射しない場合である。フッ素ゴムを介して音響波をフローセル内に照射する場合、キャリーオーバーＣ_Oは、Ｖ_PP＝３５の時、音響波をフローセル内に照射しない時のキャリーオーバーＣ_O（Ｖ_PP＝０）の約１／１．５であり、Ｖ_PP＝７０の時、キャリーオーバーＣ_Oは殆ど０である。しかし、フッ素ゴムガスケット３２３の代りに、ＰＥＥＫ板を使用する構成のフローセルを使用し、ＰＥＥＫを介して音響波をフローセル内に照射する場合、図１２の点△に示す様に、キャリーオーバーＣ_Oは、Ｖ_PP＝７０としても、音響波をフローセル内に照射しない時のキャリーオーバーＣ_O（Ｖ_PP＝０）と変化がなく、音響波の照射の効果は全く無かった。なお本実施例では、音響波の定在波の節で発生した気泡の捕捉と、気泡の移動を行なっていない。
【００９５】
（第１２の実施例）
以上の各実施例では、常に作用電極に於いて溶液の電気分解を行ない、気泡を発生させ、音響波の定在波の節で発生した気泡の捕捉と、気泡の移動を行ない、作用電極の表面に存在する物質を除去する。しかし、作用電極の表面で溶液の電気分解ができない場合や、フローセル内部の作用電極が配置さる面以外の表面に存在する物質を除去する必要がある場合もある。また、図１、図１１に示すフローセルに於いて、作用電極１１を、ＩＴＯ等の透明電極、白金等の蒸着薄膜で形成する場合、作用電極１１の面に於ける溶液の電気分解は作用電極１１の寿命を著しく劣化させることがある。
【００９６】
図１３は、本発明の第１２の実施例に於いて、溶液の電気分解を専用に行なう電気分解用電極を配置した、フロースルー型検出器のフローセルの概略の構成を示す図である。図１３に示す様に、フローセル内での電解質溶液の流れの上流側、即ち、電解質溶液がフローセル内に流入するｙ方向の矢印１１４の側で、フローセル内の底面に電気分解用電極１０１を配置する。図１、図１０、図１１の構成に電気分解用電極１０１を配置して良いことはいうまでもない。
【００９７】
液相の電位に対する電気分解用電極１０１の電位を、水の電気分解電位以上に設定し、電気分解用電極１０１の表面で水溶液の電気分解を行ない、気泡を発生させる。電気音響変換器１６、１５（図１と同様に配置されるが、図１３では図示せず）を駆動し音響波を発生させ、フローセル内の底面に音響波の定在波の節を形成し、電気分解用電極１０１で発生した気泡を音響波の定在波の節で捕捉し、先に説明した各実施例の方法により、気泡をフローセル内の底面で移動させ、フローセル流路内の洗浄を、作用電極１１を劣化させることなく、効率よりできる。更に、電気音響変換器１６、１５の、図１３に示すｙ方向の長さをより長くして、フローセル内の底面のより広い領域の洗浄が可能となる。
【００９８】
（第１３の実施例）
図１４は、本発明の第１３の実施例の電気化学発光（以下、ＥＣＬと略記する）免疫分析装置の概略の構成を示す図である。本実施例では、フロースルー型のＥＣＬ検出セルの作用電極、フローセル流路の底面の表面から磁性微粒子を洗浄により除去する。本実施例の装置は、試料を収納する試料容器１と、反応試薬を収納する反応試薬容器２と、洗浄試薬を収納する洗浄試薬容器３と、分取器４と、２つの電気音響変換器１５、１６を有するフロースルー型のＥＣＬ検出セル５と、磁石６と、光検出器７と、ポンプ８と、ポテンシオスタット１４と、駆動制御部（回路）１７と、制御部９とから構成される。
【００９９】
図１５は、試料溶液の構成を説明する図である。試料溶液は、図１５に示す様に、抗原抗体結合により検査対象物質１２１を捕捉した磁性微粒子（直径２．８μｍ）１２３と捕捉された検査対象物質１２１と結合する電気化学発光標識１２２を持つ反応生成物と、遊離の電気化学発光標識１２２と、検査対象物質１２１を捕捉していない遊離の磁性微粒子１２３とを含む懸濁液である。反応試薬は、電気化学発光反応に使用される還元剤であるトリプロピルアミンを含むリン酸緩衝液であり、洗浄試薬は、水酸化カリウム水溶液（濃度０．１Ｎ）である。なお本実施例では、発明の効果を確認するための比較試料として、予め所定の量のルテニウム（ＩＩ）トリビピリジル錯体標識を表面に固定化した磁性微粒子の懸濁液を用いた。これらの各種の溶液は、ＥＣＬ検出セル５内に矢印１１４の方向から流入し、セル下基板１１１、中間基板１１２、セル上基板１１３により形成されるフローセル流路を通り、矢印１１５の方向に流出する。
【０１００】
電気音響変換器１５、１６は、各々独立に駆動制御部１７と接続され、各々独立に制御され駆動される。ＥＣＬ検出セル５の対向電極１３−１、１３−２、電気分解用電極１０１、作用電極１１、及び参照電極１２は、ポテンシオスタット１４に接続する。制御部９は、分取器４、磁石６、ポテンシオスタット１４、ポンプ８、駆動制御部１７を、測定シーケンスに基づいて制御すると共に、ＥＣＬ検出セル５での発光を光検出器７で検出した結果を記録する。
【０１０１】
本実施例のＥＣＬ検出セル５は、図１に示す構成とほぼ同じである。セル下基板１１１は耐溶液性の良いＰＥＥＫである。電気分解用電極１０１、及び作用電極１１は白金電極である。対向電極１３−１、１３−２が配置されるセル上基板１１３は、光透過性のアクリル板である。電気音響変換器１５が配置された中間基板部材１１２−１と電気音響変換器１６が配置された中間基板部材１１２−２からなる中間基板１１２は、厚さ０．５ｍｍのフッ素ゴム平板である。中間基板部材１１２−１、１１２−２は、フッ素ゴム平板が所望の形状にレーザー切断されて形成され、フローセル流路を形成すると共にガスケットとして使用される。
【０１０２】
電気音響変換器１５、１６は、直方体の形状のＰＺＴであり、対向面に電極が設けられる。これら電極間に交流電圧を印加すると、電気音響変換器が電極間の方向に厚み振動を行ない、音響波が発生する。電極間の厚さは、電気音響変換器の共振周波数を決定するが、電気音響変換器１５、１６の共振周波数は、共に約１．０ＭＨｚとした。ＰＺＴの分極と垂直な一方の辺の長さをガスケットの厚さ未満とし、分極と垂直な他方の辺の長さを、作用電極１１の長さ以上とした。即ち、図１４に示す様に、矢印１１４と矢印１１５を結ぶ方向での電気音響変換器１５、１６の長さは、矢印１１４と矢印１１５を結ぶ方向での作用電極１１の長さ以上とする。
【０１０３】
次に、本実施例の装置の動作について詳細に説明する。本実施例の装置の動作は、（１）ＥＣＬ検出セル５への試料の導入、（２）ＥＣＬ検出セル５への反応試薬の導入、（３）電気化学発光反応の生起と電気化学発光の検出、（４）ＥＣＬ検出セル５の洗浄、及び（５）作用電極１１を再生する工程から構成される。
【０１０４】
これら工程のうち、工程（１）、（２）、（３）、及び（５）は、従来の技術と同様に行なう。工程（１）では、磁石６をＥＣＬ検出セル５の作用電極に近づけた状態で試料溶液を導入し、磁性微粒子１２３をＥＣＬ検出セル５の内部に保持する。工程（２）では、ＥＣＬ検出セルの５フローセル流路に反応試薬（薬還元剤であるトリプロピルアミンを含むリン酸緩衝液）を流入し、磁性微粒子１２３以外の物質をＥＣＬ検出セル５の外部に流出させ、フローセル流路内に反応試薬に囲まれる磁性微粒子１２３が残る。工程（３）では、磁石６をＥＣＬ検出セル５から離し、作用電極１１とフローセル流路内の液相の間の電位を電気化学発光反応電位とし、電気化学発光反応を生起させて、この結果作用電極１１の面に於いて生じる電気化学発光の発光強度を光検出器７で測定する。なおこの発光強度は、試料溶液中に存在する検査対象物質を標識する電気化学発光標識１２２の量、即ち検査対象物質の量に比例する。工程（５）では、反応試薬を再度導入して作用電極１１を再生する。
【０１０５】
従来の技術に於ける工程（４）では、ＥＣＬ検出セル５のフローセル流路に洗浄試薬を流入し、同時に作用電極１１とフローセル流路の液相の間の電位を水の電気分解電位以上に設定して作用電極１１の表面で気泡を発生させ、作用電極の表面の物質を、気泡の作用、及び洗浄試薬の流れの作用とにより除去する。
【０１０６】
本実施例の装置での工程（４）では、作用電極１１の表面に存在する磁性微粒子をＥＣＬ検出セル５の外部へ除去する。本発明の洗浄工程では、従来技術の工程（４）での、水の電気分解により生成した気泡の作用、及び洗浄試薬の流れの作用に、更に新たな作用を付加して洗浄を行なう。即ち、先に説明した第３から第９の各実施例で説明した様に、交流、又は矩形波の電圧波形を用い、電気音響変換器１６、１５を各種変調法で電圧駆動して、音響波の定在波の節の位置（気泡が捕捉される位置）を広い範囲で変化させ、気泡を広い範囲で捕捉し、作用電極１１の表面全体を含む広い面に物理的な力を作用させて、作用電極１１の表面全体を含む広い面の洗浄を効率良く行ない、洗浄性能を向上させる。高分子ゴム（フッ素ゴム）を介して音響波をフローセル内に照射して洗浄を効率を更に向上させる。
【０１０７】
本実施例では、以下の４種類の実験条件で、洗浄工程の洗浄性能を比較した。なお本実施例では、電気分解による気泡の発生では、図１１に示す電気分解用電極１０１を使用せず、作用電極１１を使用し、工程（１）、（２）、（３）、及び（５）は、従来の技術と同条件で行なった。
【０１０８】
実験−１：従来の技術に於ける工程（４）を使用する実験。
【０１０９】
実験−２：本発明の第３の実施例の（図３）で説明した条件で、周波数を正弦的に周期的に変化させる「周波数変調法」により２つの電気音響変換器を駆動し、音響波の定在波の節の位置を変化させる工程（４）を使用する実験。
【０１１０】
実験−３：本発明の第４の実施例の（図５）で説明した条件で、周波数を線形的に周期的に変化させる「周波数変調法」により２つの電気音響変換器を駆動し、音響波の定在波の節の位置を変化させる工程（４）を使用する実験。
【０１１１】
実験−４：実験−２に於いて、「周波数変調法」は採用しない工程（４）を使用する実験（従って、音響波の定在波の節の移動は生じていない））。
【０１１２】
洗浄性能の評価は、測定試料として試料溶液を用いて、工程（１）、（２）、（３）を実行して、発光強度Ｓ₁を計測し、発光強度Ｓ₁を計測の後、実験−１、実験−２、実験−３に対応する工程（４）を各々実行し、次に工程（５）を実行して、ＥＣＬ検出セル５のフローセル流路に新規に試料溶液を導入せずに、ＥＣＬ検出セル５に残留する成分による発光強度Ｓ₂’を各々測定し、フローセルのキャリーオーバー（異なる試料の間の検体混入）Ｃ_OをＣ_O＝Ｓ₂’／Ｓ₁により定義し、各種の洗浄方法に於けるキャリーオーバーを比較した。
【０１１３】
図１６は、各種の洗浄方法による、洗浄時間とキャリーオーバーＣ_Oの比較結果を示す図である。図１６の横軸は洗浄時間であり、Ｔ₀は従来技術での洗浄時間である。図１６に於いて、●印のプロット１３１は、実験−１の洗浄工程（従来技術）でのキャリーオーバーＣ_O、□印のプロット１３２は、実験−２の洗浄工程でのキャリーオーバーＣ_O、○印のプロット１３３は、実験−３の洗浄工程でのキャリーオーバーＣ_O、△印のプロット１３４は、実験−４の洗浄工程でのキャリーオーバーＣ_Oを示す。なお、図１６に示す洗浄時間は、図１２の結果を得た時の洗浄時間と異なり、図１６と図１２の結果を得る時に使用したフローセルの寸法、形状は異なっている。
【０１１４】
図１６に示す結果から、実験−２、実験−３では、洗浄時間を従来技術での洗浄時間Ｔ₀と同時間とする時、キャリーオーバーＣ_Oは従来技術での約１／３であり、洗浄時間を従来技術での洗浄時間Ｔ₀の１／２とする時、キャリーオーバーＣ_Oは従来技術での約１／８となり、更に、実験−２、実験−３では、洗浄時間を従来技術での洗浄時間Ｔ₀と同時間としても１／２の時間としても、キャリーオーバーＣ_Oはほぼ同程度であり、実験−２、実験−３では洗浄時間の短縮が実現できる。また、プロット１３４とプロット１３２、１３３との比較から、音響波の定在波の節の移動を生じさせることが、洗浄性能の向上に大きく寄与し、キャリーオーバーの減少を短時間で実現していることが明確である。
【０１１５】
【発明の効果】
本発明によれば、交流、又は矩形波の電圧波形を用い、電気音響変換器を各種変調法の電圧駆動により、音響波の定在波の節の位置（気泡が捕捉される位置）を広い範囲で変化させ、気泡を広い範囲で捕捉し、作用電極の表面全体を含む広い面に物理的な力を作用させて、作用電極の表面全体を含む広い面の洗浄を効率良く行ない、洗浄性能を向上できる。高分子ゴム（フッ素ゴム）を介して音響波をフローセル内に照射して洗浄の効率を更に向上させる。
【０１１６】
特に、検査対象物質を磁性微粒子を用いて捕捉した後に検出（測定）をフロースルー方式により行なう化学分析装置、電気化学発光免疫分析装置のフローセルの洗浄効率の向上、洗浄時間の短縮が可能となり、分析精度の向上、分析所要時間の短縮、洗浄溶液の総量の減少が可能となり、計測のスループット向上、低コスト化が実現できる。
【図面の簡単な説明】
【図１】本発明の第１の実施例のフロースルー型検出器の構成を示す図。
【図２】本発明の第２の実施例に於いて、フローセル流路に形成される定在波の状態を説明する図。
【図３】本発明の第３の実施例に於いて、「周波数変調法」による音響波の定在波の節の位置の変化を説明する図。
【図４】本発明の第３の実施例に於いて、音響波の定在波の節の位置の変化の詳細を説明する図。
【図５】本発明の第４の実施例に於いて、「周波数変調法」による音響波の定在波の節の位置の変化を説明する図。
【図６】本発明の第５の実施例に於いて、「周波数変調法の改良法」により定在波の節の空間的分布を任意に変化させることを説明する図。
【図７】本発明の第６の実施例に於いて、「位相変調法」による音響波の定在波の節の位置の変化を説明する図。
【図８】本発明の第８の実施例に於いて、「組合わせ法」による音響波の定在波の節の位置の変化を説明する図。
【図９】本発明の第９の実施例に於いて、電気音響変換器を駆動する矩形波を示す図。
【図１０】本発明の第１０の実施例に於いて、フロースルー型検出器のフローセルの構成を示す図。
【図１１】本発明の第１１の実施例に於いて、電気化学発光反応を利用するフロースルー型化学分析装置のフローセルを示す図。
【図１２】本発明の第１１の実施例に於いて、キャリーオーバーＣ_OとＰＺＴの駆動電圧振幅（Ｖ_PP）との関係を示す図。
【図１３】本発明の第１２の実施例に於いて、溶液の電気分解を専用に行なう電極を配置した、フロースルー型検出器のフローセルの概略の構成を示す図。
【図１４】本発明の第１３の実施例に於いて、電気化学発光免疫分析装置の概略の構成を示す図。
【図１５】本発明の第１３の実施例に於いて、試料溶液の構成を説明する図。
【図１６】本発明の第１３の実施例に於いて、各種の洗浄方法による、洗浄時間とキャリーオーバーＣ_Oの比較結果を示す図。
【符号の説明】
１…試料容器、２…反応試薬容器、３…洗浄試薬容器、４…分取器、５…フロースルー型のＥＣＬ検出セル、６…磁石、７…光検出器、８…ポンプ、９…制御部、１１…作用電極、１２…参照電極、１３−１、１３−２…対向電極、１４…ポテンシオスタット、１５…電気音響変換器、１６…電気音響変換器、１７…駆動制御部、２２−１、２２−２…定在波、２３−１、２３−２、２３−３、２３−４…定在波の節、２４…定在波の隣り合う節の間の距離、２５…定在波の節の部分であって作用電極の表面近傍の領域、２６…フローセル内の溶液を流れ方向、６１…位相差が無い場合の音響波の定在波の節の位置、６２…位相差が有る場合の音響波の定在波の節の位置、６３…音響波の定在波の節の位置の移動距離、６４…定在波中間面、７１…定在波の節の移動の方向、８１…周波数ｆ₂（ｔ）の時間変化、８２…周波数ｆ₁（ｔ）の時間変化、８３…周波数ｆ₂（ｔ）とｆ₁（ｔ）との差、８４…定在波中間面、８５、８６…「うなり法」での音響波の定在波の節の移動経路、１０１…電気分解用電極、１１１…セル下基板、１１２−１、１１２−２…中間基板部材、１１２…中間基板、１１３…セル上基板、１２１…検査対象物質、１２２…電気化学発光標識、１２３…磁性微粒子、１３１…実験−１の洗浄工程でのキャリーオーバー、１３２…実験−２の洗浄工程でのキャリーオーバー、１３３…実験−３の洗浄工程でのキャリーオーバー、１３４…実験−４の洗浄工程でのキャリーオーバー、２１１…平板電極、２２１…線電極、２２２…流入口、２２３…排出口、２３１…フローセル流路、２４１、２４２…圧電素子、３１１…流入口、３１２…排出口、３１３…高分子ゴム、３１４…電気音響変換器、３１５…磁石、３１６…セル部、３１７…上部板、３２１…下基板、３２２…上基板、３２３…フッ素ゴムガスケット、４１２、４２２、４３２…定在波中間面、４１３、４１４、４２３、４２４、４３３…定在波の節に捕捉される気泡の位置、４４３、４４４…定在波の節に捕捉された気泡の移動範囲。[0001]
BACKGROUND OF THE INVENTION
The present invention is a flow-through type for detecting chemical substances. apparatus And an electrochemiluminescence immunoassay apparatus using the same Do .
[0002]
[Prior art]
As a method for detecting an interesting test target substance in a sample, there is a method using magnetic fine particles that specifically bind to the test target substance. In this method, for example, when the content of the test target substance in the sample is extremely small, such as immunoassay, and it is necessary to selectively test the test target substance, the test target substance is bound to the magnetic fine particles and magnetic force is applied. It is selected using. On the other hand, there is a flow-through method using a flow cell as a chemical measurement system suitable for automation. In this method, it is possible to quickly change between the initial stage of cleaning and conditioning the flow cell and the measurement stage. In the initial stage of cleaning and conditioning, hydrodynamic cleaning is used. In the hydrodynamic cleaning, the inside of the flow cell in which the cleaning solution is circulated through the flow cell is cleaned, so that liquid is always present in the flow cell and is not exposed to air, so that no external factors are mixed in the measurement. In addition, a plurality of different samples can be measured without disassembling the apparatus, and an improvement in measurement throughput can be expected. As an example of the prior art, there is an electrochemiluminescence measuring apparatus described in Japanese Patent Publication No. 7-6912.
[0003]
[Problems to be solved by the invention]
In flow-through chemical analyzers that use flow cells, improving flow cell cleaning (washing) efficiency is very important from the standpoint of improving measurement accuracy. However, there is a problem that the measurement history is affected and the measurement accuracy is lowered. In particular, in an automatic analyzer that continuously measures different samples, there is a problem that sample mixing (carry over) between different samples occurs, and accurate measurement cannot be performed.
[0004]
However, when the detection target substance is captured using magnetic fine particles and then detected (measured) by the flow-through method, it is very difficult to clean the magnetic fine particles after the measurement. Magnetic fine particles may enter slight gaps, boundaries, scratches, etc. of the flow cell, and may remain in the flow cell without being removed by cleaning as they are, and the time required for cleaning the flow cell becomes longer and required per inspection. There is a problem that the time is increased and the total amount of the buffer solution required for the cleaning is remarkably increased.
[0005]
The object of the present invention is to solve the above-mentioned problems of the prior art, to efficiently clean the flow cell, to shorten the cleaning time, to reduce sample contamination (carry over) between different samples, to improve analysis accuracy and to analyze It is an object of the present invention to provide a flow-through detector that realizes shortening of required time, improvement of measurement throughput, and cost reduction, and an electrochemiluminescence immunoassay apparatus using the same.
[0006]
[Means for Solving the Problems]
The flow-through detector according to the present invention changes the position of a flow cell having a flow path, an electroacoustic transducer that is sandwiched between the flow paths, and a standing wave node of an acoustic wave emitted from each electroacoustic transducer. Control means for performing control, and means for generating bubbles in the flow path (an electrode for generating bubbles by electrolysis of the aqueous solution is formed on the bottom surface of the flow path), and the position of the node of the standing wave The feature is that the position of the bubble is changed by changing.
[0007]
The control means performs any of the following controls on the AC voltage for independently driving the electroacoustic transducers. (1) The frequency of the AC voltage is periodically changed, (2) the frequency of the AC voltage is periodically changed cyclically, and (3) the frequency of the AC voltage is set to two predetermined frequencies. (4) controlling the phase difference of the AC voltage, (5) controlling the phase difference of the AC voltage to be constant, and (6) the position between the AC voltages. Changing the phase difference periodically; (7) changing the phase difference of the AC voltage linearly and periodically; (8) controlling the frequency difference of the AC voltage; and (9) changing the frequency difference of the AC voltage. And periodically changing with a predetermined constant frequency difference. That is, a drive control unit that drives and controls the electroacoustic transducer by frequency modulation, phase modulation, modulation by beat, and the like is provided to change the position of the node of the standing wave.
[0008]
The AC voltage for driving each electroacoustic transducer is preferably a rectangular wave, and a member between each electroacoustic transducer and the flow path is made of a polymer rubber, in particular, hexafluoropropylene and vinylidene fluoride. It is preferable that it is composed of a copolymer of
[0009]
Furthermore, the flow-through detector of the present invention includes a cell lower substrate on which a working electrode and a reference electrode are arranged, an intermediate substrate on which an electroacoustic transducer is arranged oppositely, and an cell upper substrate on which a counter electrode is arranged. Each of the electroacoustic transducers, and a flow control detector that independently modulates the electroacoustic transducers to control voltage drive. It is characterized in that bubbles are captured by changing the position of the standing wave node of the emitted acoustic wave, and cleaning is performed by applying a physical force to the surface of the working electrode, which drives each electroacoustic transducer The AC voltage is preferably a rectangular wave.
[0010]
The electrochemiluminescence immunoassay device of the present invention is characterized by comprising the above-described flow-through detector.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a diagram showing the configuration of a flow-through detector according to the first embodiment of the present invention. The flow cell of the flow-through detector according to the present embodiment includes a lower cell substrate 111 on which the working electrode 11 and the reference electrode 12 are disposed, an intermediate substrate member 112-1 on which the electroacoustic transducer 15 is disposed, and electroacoustic conversion. The intermediate substrate 112 made of the intermediate substrate member 112-2 on which the vessel 16 is arranged, and the on-cell substrate 113 on which the counter electrodes 13-1 and 13-2 are arranged are laminated in the z direction shown in FIG. Is done. The intermediate substrate members 112-1 and 112-2 may be formed by punching a fluororubber flat plate with a die to form a flow cell flow path and may be used as a gasket. The solution flows into the flow cell from the arrow 114 in the y direction shown in FIG. 1, passes through the flow cell flow path formed by the lower cell substrate 111, the intermediate substrate 112, and the upper cell substrate 113, and flows out in the direction of the arrow 115. . The potentials of the working electrode 11, the reference electrode 12, and the counter electrodes 13-1, 13-2 in contact with the solution passing through the flow cell channel are controlled by a potentiostat 14, and the electroacoustic transducers 15, 16 are driven and controlled. Each unit (circuit) 17 is independently controlled and driven.
[0012]
The reference electrode 12 is an electrode having the same potential as the liquid phase in the flow cell. The potentiostat 14 has a function of changing the liquid phase potential by applying a voltage to the counter electrodes 13-1 and 13-2 so that the potential difference between the reference electrode 12 and the working electrode 11 becomes a preset potential difference. Have. The traveling direction of the acoustic wave generated from the electroacoustic transducers 15 and 16 is parallel to the working electrode surface, and the traveling direction of the acoustic wave and the flow direction of the solution in the flow cell intersect each other. 16 are arranged facing each other in the x direction as shown in FIG. The drive control unit 17 includes a function generator and an amplifier, and an AC voltage waveform (V) for driving the electroacoustic transducers 16 and 15 by a preset program. ₁ (T), V ₂ (T)) is controlled to change the state of the acoustic wave applied to the flow cell channel. Generally AC voltage waveform, V ₁ (T), V ₂ (T) is V ₀₁ , V ₀₂ Amplitude, f ₁ , F ₂ The frequency, α ₁ , Α ₂ Is a phase, and t is a time variable, and is given by (Expression 1) to (Expression 2).
[0013]
[Expression 1]
V ₁ (T) = V ₀₁ sin (2πf ₁ t + α ₁ (...)
[0014]
[Expression 2]
V ₂ (T) = V ₀₂ sin (2πf ₂ t + α ₂ ) (Equation 2)
(Second embodiment)
Next, the flow-through detector of the present invention and the cleaning method thereof, particularly the method of removing the substance present on the surface of the working electrode 11 will be described in detail. First, an electrolyte solution, for example, an alkaline solution such as an aqueous potassium hydroxide solution or an aqueous sodium hydroxide solution is introduced into the flow cell channel. Next, the potential of the working electrode with respect to the liquid phase potential is set to be equal to or higher than the electrolysis potential of water, and the aqueous solution is electrolyzed on the surface of the working electrode 11 to generate bubbles. The electroacoustic transducers 16 and 15 are driven to generate acoustic waves having the same phase, frequency, and amplitude, and a standing acoustic wave is formed in the liquid phase in contact with the surface of the working electrode 11. That is, the alternating voltage waveform for driving the electroacoustic transducers 16 and 15 is expressed as V in (Equation 1) to (Equation 2). ₀₁ = V ₀₂ = V ₀ , F ₁ = F ₂ = F ₀ , Α ₁ = Α ₂ = Α, (Equation 3)
[0015]
[Equation 3]
V ₁ (T) = V ₂ (T) = V ₀ sin (2πf ₀ t + α) (Equation 3)
FIG. 2 is a diagram illustrating a state of a standing wave formed in the flow cell channel. 2A is a cross-sectional view including the surface of the working electrode 11 in the flow cell channel, and FIG. 2B is a cross section perpendicular to the surface of the working electrode 11 taken along a dotted line 21 shown in FIG. FIG. In FIG. 2, 22-1 and 22-2 represent standing waves formed in the liquid phase by the electroacoustic transducers 15 and 16 in a transverse wave display. In FIG. 2, the position of the node of the standing wave of the acoustic wave is indicated by dotted lines 23-1, 23-2, 23-3, 23-4, and the distance 24 between adjacent nodes of the standing wave is the acoustic wave. Corresponds to half the wave wavelength. Since the diameter of most bubbles generated by electrolysis exceeds 10 μm, when the frequency of the standing wave is set to 500 kHz or more, the bubbles generated by electrolysis collect in a region where the sound pressure of the standing wave is low.
[0016]
In the present embodiment, the sound pressure of the standing wave is minimized in a region 25 (white circle shown in FIG. 2) in the vicinity of the surface of the working electrode 11 which is the node of the standing wave. As a result, bubbles generated on the surface of the working electrode 11 gather in the region of the white circle 25 and are trapped, and further, due to the sound pressure of the standing wave formed in the flow cell channel, the surface direction of the working electrode 11 (−z direction). ) Under pressure. The bubbles pressed against the surface of the working electrode 11 by this pressure exert (act) a physical force on the substance existing on the surface of the working electrode 11. When flowing the solution in the flow cell in the flow direction 26 (y direction), the bubbles flow on the surface of the working electrode 11 in the direction 27 (y direction) along the nodes 23-1 to 23-4 of the standing wave. As a result, the bubbles act (apply) the substance present on the surface of the working electrode 11 so as to flow in the direction 27 (y direction), and the substance on the surface of the working electrode 11 can be efficiently removed.
[0017]
The position of the node of the standing wave of the acoustic wave formed in the flow cell channel is periodically changed in the direction (X direction) intersecting with the solution flow direction 26 (y direction), so that the sound of the standing wave is obtained. A force (action) due to pressure is widely applied to the entire surface of the working electrode 11, and bubbles trapped on the surface of the working electrode 11 are moved widely over the surface of the working electrode 11, so that the material on the surface of the working electrode 11 can be removed with high efficiency. Can be realized. In the following examples, various methods for changing the position of trapping bubbles by periodically changing the position of a standing wave node of an acoustic wave will be described.
[0018]
(Third embodiment)
FIG. 3 is a diagram for explaining the change in the position of the node of the standing wave of the acoustic wave (position where the bubble is captured) by the “frequency modulation method”. FIG. 4 is a diagram for explaining the details of the change in the position of the node of the standing wave of the acoustic wave, and is a cross-sectional view perpendicular to the surface of the working electrode 11 taken along the dotted line 21 shown in FIG. The “frequency modulation method” in which the electroacoustic transducers 16 and 15 are driven to periodically change the frequency of the acoustic wave irradiated in the flow cell channel will be described below. In the present embodiment, the frequency of the acoustic wave forming the standing wave is changed with a sufficiently large period T as compared with the frequency of the acoustic wave, and the standing wave node is maintained while retaining the standing wave of the acoustic wave. Change the position of.
[0019]
For example, as shown in FIG. 3A, the frequency of the acoustic wave is changed sinusoidally, and the frequency f in (Equation 3) is changed. ₀ Is replaced by f (t) shown in (Equation 4), and the electroacoustic transducers 16 and 15 are driven by the frequency-modulated AC voltage waveform shown in (Equation 5). In the example shown in FIG. 3, the period is T = 0.25 sec (4 Hz). The arrow shown in FIG. 3B indicates the change in the position of the node of the standing wave of the acoustic wave when the frequency of the acoustic wave is changed sinusoidally as shown in FIG. As shown in FIG. 3B, the position of the node of the standing wave of the acoustic wave changes periodically, and moves in the order of 414 → 424 → 413 → 423 → 433 →.
[0020]
[Expression 4]
f (t) = f ₀ + Δfsin (2πt / T) (Expression 4)
[0021]
[Equation 5]

4 (A), 4 (B), and 4 (C), the frequency of the acoustic wave is fixed at each time point where f (t) = 1.0 MHz, 1.4 MHz, and 0.6 MHz, respectively. It is a figure which shows a standing wave by a transverse wave display. 4 (A), 4 (B), and 4 (C), the interval between the standing wave nodes at each time point is expressed as d. ₁ (411), d ₂ (421), d _Three (431) When the sound speed in the solution is about 1500 m / sec, d ₁ ≒ 0.75mm, d ₂ ≒ 0.54mm, d _Three ≈1.25 mm. The electroacoustic transducers 15 and 16 are arranged in parallel while maintaining the distance D.
[0022]
4A, 4B, and 4C, the acoustic wave transmission time by the electroacoustic transducer 15 is equal to the acoustic wave transmission time by the electroacoustic transducer 16. Is indicated by dotted lines 412, 422, 432. In the following description, the planes indicated by dotted lines 412, 422, and 432 are represented as “standing wave intermediate planes” for simplicity. When the acoustic wave transmission paths by the electroacoustic transducers 15 and 16 are acoustically equivalent, the standing wave intermediate planes are surfaces that are at equal distances from the electroacoustic transducers 15 and 16 shown in FIG. .
[0023]
Hereinafter, the movement of the node of the standing wave when the frequency of the acoustic wave is changed will be described with reference to FIGS. 4 (A), 4 (B), and 4 (C). A standing wave node on the left side of the standing wave intermediate plane (hereinafter referred to as “left first section”) and a second standing wave node on the right side of the standing wave intermediate plane (hereinafter referred to as “right first section”). This will be described by way of example.
[0024]
At the time point (a) shown in FIG. 3 (A), the frequency of the acoustic wave is f (t) = 1.0 MHz, and the position of the bubble trapped in the first left node is x shown in FIG. 4 (A). A position 413 in the direction. Between the time point (a) and the time point (b) shown in FIG. 3 (A), when the frequency of the acoustic wave changes in a higher direction and reaches f (t) = 1.4 MHz at the time point (b), The bubble moves to a position 423 in the x direction shown in FIG. Next, between the time point (b) and the time point (c) shown in FIG. 3 (A), the frequency of the acoustic wave changes in a lower direction and reaches f (t) = 1.0 MHz at the time point (c). Then, the bubble returns to the position 413 in the x direction shown in FIG. Between the time point (c) and the time point (d) shown in FIG. 3 (A), the frequency of the acoustic wave changes in a lower direction, and reaches f (t) = 0.6 MHz at the time point (d). The bubbles move to the position 433 in the x direction shown in FIG.
[0025]
Further, between the time point (d) and the time point (e) shown in FIG. 3 (A), the frequency of the acoustic wave changes again in a higher direction, and at time (e), f (t) = 1.0 MHz. When it reaches, the bubble returns to the position 413 in the x direction. In this way, the range of movement of the bubbles trapped in the left first node by the frequency modulation of the acoustic wave shown in FIG. 3A is as shown in FIG. 4D every cycle T (0.25 sec). The region 443 in the x direction is moved to a position to exert a force on (act on) the substance in the region 443 on the surface of the working electrode 11.
[0026]
At the time point (a) shown in FIG. 3 (A), the frequency of the acoustic wave is f (t) = 1.0 MHz, and the position of the bubble trapped in the right second node is x shown in FIG. 4 (A). A position 414 in the direction. Between the time point (a) and the time point (b) shown in FIG. 3 (A), when the frequency of the acoustic wave changes in a higher direction and reaches f (t) = 1.4 MHz at the time point (b), The bubble moves to a position 424 in the x direction shown in FIG. Next, between the time point (b) and the time point (c) shown in FIG. 3 (A), the frequency of the acoustic wave changes in a lower direction and reaches f (t) = 1.0 MHz at the time point (c). Then, the bubbles reach the wall surface (112-2) of the flow cell channel via the position 414 in the x direction shown in FIG.
[0027]
Between the time point (c) and the time point (d) shown in FIG. 3 (A), the frequency of the acoustic wave changes in the lower direction, and the bubbles reach the wall surface (112-2) in the x direction of the flow cell channel. Later, when the frequency of the acoustic wave further changes, the standing wave node comes out of the flow cell channel, and the bubbles trapped in the standing wave node diffuse. After reaching f (t) = 0.6 MHz at time (d), the node of the standing wave again enters the flow cell channel between time (d) and time (e) shown in FIG. Return and new bubbles are captured. In this way, the range of movement of the bubbles trapped in the right second section by the frequency modulation of the acoustic wave shown in FIG. 3A is as shown in FIG. 4D every cycle T (0.25 sec). The region 444 in the x direction is moved to a position to apply a force to the substance in the region 444 on the surface of the working electrode 11.
[0028]
As described above, in this embodiment, the nodes of the standing wave (left first node, right second node) and the bubbles trapped in these are moved in the x-direction ranges 443 and 444 in 1 second (1 / T ) Reciprocate only times to push away the substances present in the surface areas 443 and 444 of the working electrode 11. In the frequency modulation method, the position of the standing wave intermediate plane is important. When the frequency of the acoustic wave increases, the position of the node of the standing wave of the acoustic wave (the position where the bubble is captured) always moves in the direction approaching the standing wave intermediate plane. Further, when the frequency of the acoustic wave decreases, the position of the node of the standing wave of the acoustic wave (the position where the bubble is trapped) always moves in a direction away from the standing wave intermediate plane.
[0029]
(Fourth embodiment)
FIG. 5 is a diagram for explaining a change in the position of the node of the standing wave of the acoustic wave (position where the bubble is captured) by the “frequency modulation method”. In the third embodiment, the frequency of the acoustic wave is changed sinusoidally, but in this embodiment, the frequency f in (Equation 3) is changed. ₀ Is replaced by a periodic function f (t) expressed by (Equation 6) to (Equation 8), and the electroacoustic transducers 16 and 15 are driven by a frequency-modulated AC voltage waveform expressed by (Equation 11).
[0030]
[Formula 6]
f (t) = f _min + (F _max -F _min ) (T / T) (Expression 6)
However, the periodic function f (t) of (Equation 6) has a period T, satisfies (Equation 7) to (Equation 8), and is between t = nT and t = (n + 1) T (n = 0, 1 2,... F (t) increases linearly and monotonously. Frequency f in (Equation 4) ₀ , Δf, and f _min , F _max (Equation 9) to (Equation 10).
[0031]
[Expression 7]
f (t = nT; n = 0, 1, 2,...) = f _min (Starting frequency) ... (Formula 7)
[0032]
[Equation 8]
f (t → nT; n = 0, 1, 2,...) → f _max (End point frequency) (Equation 8)
[0033]
[Equation 9]
2f ₀ = (F _min + F _max ) (Equation 9)
[0034]
[Expression 10]
2Δf = (f _max -F _min ) (Equation 10)
[0035]
[Expression 11]

FIG. 5A shows a periodic function f (t) in which the frequency of the acoustic wave is expressed by (Expression 6) to (Expression 8), that is, the starting frequency f. _min To end frequency f _max Up to now, an example of frequency modulation in which a linear change is repeated monotonously will be shown. In FIG. 5A, the period T = 0.25 sec (4 Hz), f _min = 0.6MHz, f _max = 1.4MHz, f ₀ = 1 MHz, Δf = 0.4 MHz. The arrow shown in FIG. 5B indicates the change in the position of the node of the standing wave of the acoustic wave when the frequency of the acoustic wave is linearly and periodically changed, as shown in FIG. 5A. . As shown in FIG. 5 (B), the position of the node of the standing wave of the acoustic wave changes periodically and moves in the order of → 414 → 424 → 433 → 413 → 423 →.
[0036]
The frequency of the acoustic wave at each of the time points (a), (b), and (c) shown in FIG. 5 (A) is the time point (d), (a), (b) shown in FIG. 3 (A). ) Equal to the frequency of the acoustic wave in each of The standing wave states at time points (a), (b), and (c) shown in FIG. 5 (A) are as shown in FIGS. 4 (C), 4 (A), and 4 (B), respectively. Are the same. However, the time point (c) in FIG. 5 (A) immediately moves to the time point (d), and the state of the standing wave also returns from the state in FIG. 4 (B) to the state in FIG. 4 (C).
[0037]
In this embodiment, as in the third embodiment, the bubbles trapped in the standing wave nodes (left first node, right second node) are moved within the movement ranges 443 and 444 shown in FIG. Are repeatedly moved toward the standing wave intermediate plane. In this embodiment, f _min (Starting frequency) <f _max When (end-point frequency), the node of the standing wave always moves toward the standing wave intermediate plane. _min (Starting frequency)> f _max At (end point frequency), the node of the standing wave always moves away from the standing wave intermediate plane. That is, in this embodiment, the position of the standing wave intermediate surface is adjusted so as to come to the center of the flow cell flow, and f _min (Starting frequency) <f _max The (end-point frequency) can be controlled so that the material on the surface of the working electrode 11 is always collected at the center of the flow cell.
[0038]
(Fifth embodiment)
FIG. 6 is a diagram for explaining arbitrarily changing the spatial distribution of the standing wave nodes by the “improved method of frequency modulation method”, and the working electrode 11 at the dotted line 21 shown in FIG. It is sectional drawing perpendicular | vertical to the surface of this. In the third embodiment, since the electroacoustic transducers 16 and 15 are driven with the same phase by the frequency-modulated AC voltage waveform shown in (Equation 5), the phases of the two acoustic waves coincide with each other. The standing wave intermediate plane is always the portion with the maximum amplitude. For example, as an improvement of the frequency modulation method shown in the third embodiment, the frequency-modulated AC voltage waveform V shown in (Equation 12) to (Equation 13) is used. ₁ (T), V ₂ Phase α of (t) ₁ , Α ₂ Phase difference (α ₂ -Α ₁ ) To arbitrarily change the spatial distribution of standing waves of acoustic waves.
[0039]
[Expression 12]

[0040]
[Formula 13]

For example, as shown in FIG. 6A, the frequency-modulated AC voltage waveform V that drives the electroacoustic transducer 15 is used. ₂ Phase t of (t) ₂ And frequency-modulated AC voltage waveform V for driving the electroacoustic transducer 16 ₁ Phase t of (t) ₁ When the difference in phase (phase difference) is represented by (Equation 14), the node of the standing wave is in the direction away from the electroacoustic transducer 15 (in FIG. 6A, the negative direction of the x axis). Is moved by a distance equal to β / 4. The dotted line 61 indicates the position of the node of the standing wave of the acoustic wave when there is no phase difference (β = 0), and the dotted line 62 indicates the position of the node of the standing wave of the acoustic wave when there is a phase difference (β ≠ 0). The position of the standing wave node of the acoustic wave is moved by the moving distance 63.
[0041]
[Expression 14]

Further, in equation (14), β = 1, and as shown in FIG. 6B, the phase difference is π, that is, the phase α ₂ The phase α ₁ On the other hand, when it advances by π, the node of the standing wave is equal to ¼ of the wavelength of the acoustic wave in the direction away from the electroacoustic transducer 15 (the negative direction of the x axis in FIG. 6B). Since it moves by the distance, it can be changed so that the standing wave intermediate plane 64 is always a node of the standing wave. In the method of the present embodiment, the position of the node of the standing wave of the acoustic wave (position where the bubble is captured) can be arbitrarily adjusted.
[0042]
(Sixth embodiment)
FIG. 7 is a diagram for explaining the change in the position of the node of the standing wave of the acoustic wave (position where the bubble is trapped) by the “phase modulation method”, and the action on the dotted line 21 shown in FIG. 2 is a cross-sectional view perpendicular to the surface of an electrode 11. FIG. In this embodiment, the electroacoustic transducers 16 and 15 are frequency-modulated AC voltage waveforms V shown in (Expression 15) to (Expression 16). ₁ (T), V ₂ Phase t of (t) ₁ , Α ₂ Difference (phase difference (α ₂ -Α ₁ )) Is driven by the time-varying phase modulation method to change the position of the standing wave node of the acoustic wave.
[0043]
[Expression 15]
V ₁ (T) = V ₀ sin {2πf ₀ t + α ₁ (T)} (Equation 15)
[0044]
[Expression 16]
V ₂ (T) = V ₀ sin {2πf ₀ t + α ₂ (T)} (Expression 16)
For example, the AC voltage waveform V with respect to the electroacoustic transducer 16 in FIG. ₁ Phase t of (t) ₁ (T) and AC voltage waveform V for the electroacoustic transducer 15 ₂ Phase t of (t) ₂ Difference from (t), {α ₂ (T) -α ₁ (T)} (phase difference) is changed with time according to (Equation 17).
[0045]
[Expression 17]
α ₂ (T) -α ₁ (T) = 2πt / T (Equation 17)
FIG. 7B shows the phase difference {α at T = 0.375 sec (2.7 Hz). ₂ (T) -α ₁ (T)} shows the time change and the change amount of the position of the node of the standing wave of the acoustic wave. Phase difference {α ₂ (T) -α ₁ (T)} and the change amount h (t) of the position of the node of the acoustic wave standing wave have a proportional relationship shown in (Equation 18). The position is a value on the right vertical axis in FIG. Note that d is a distance between nodes of the standing wave as shown in FIG. The node of the standing wave moves at a constant velocity d / T in the direction of the arrow 71 shown in FIG. The phase difference 2π is physically equal to the phase difference zero, and the change in the position of the node of the standing wave of the acoustic wave in this embodiment is repeated at the period T.
[0046]
[Expression 18]
h (t) = {α ₂ (T) -α ₁ (T)} d / (2π) = (t / T) d (Equation 18)
In this embodiment, the frequency f of the acoustic wave ₀ In order to move the position of the node of the standing wave of the acoustic wave (the position where the bubbles are trapped) in a wide range, the position of the node of the standing wave of the acoustic wave is moved in a wide range. The bubbles having the function of cleaning the surface can be moved in a wide range, which is effective when the entire surface of the working electrode 11 is cleaned.
[0047]
(Seventh embodiment)
In this embodiment, the AC voltage waveform V that drives the electroacoustic transducers 16 and 15 is used. ₁ (T), V ₂ The node of the standing wave of the acoustic wave is moved in one direction by the “beat method” in which the acoustic wave is generated by slightly shifting the frequency of (t) and the flow cell flow path is irradiated. The AC voltage waveform for driving the electroacoustic transducers 16 and 15 is expressed as V in (Equation 1) to (Equation 2). ₀₁ = V ₀₂ = V ₀ , F ₁ = F ₀ , F ₂ = F ₀ + Δf, α ₁ = Α ₂ = Α, (Equation 19) to (Equation 20). For example, f ₁ = F ₀ The electroacoustic transducers 16 and 15 are vibrated with = 1 MHz and δf = 2 Hz.
[0048]
[Equation 19]
V ₁ (T) = V ₀ sin (2πf ₀ t + α) (Equation 19)
[0049]
[Expression 20]
V ₂ (T) = V ₀ sin {2π (f ₀ + Δf) t + α} (Equation 20)
At this time, in the space between the electroacoustic transducers 15 and 16, a standing wave substantially equivalent to a standing wave generated by an acoustic wave having a frequency of 1 MHz is formed, and the antinodes and nodes of the standing wave are It moves at a moving speed v in the direction of an electroacoustic transducer (electroacoustic transducer 15 in the above example) driven at a relatively high frequency. The standing wave antinode and the moving speed v of the node are λ _m Is given by (Equation 21) as the average value of the wavelengths in the liquid phase of the acoustic waves emitted from the electroacoustic transducers 16 and 15, and in this embodiment δf = 2 Hz, and the sound velocity in the liquid phase is 1500 m / If it is sec, λ _m ≈1.5 mm and v≈3.0 mm / sec.
[0050]
[Expression 21]
v = δfλ _m ... (Formula 21)
In the present embodiment, the node of the standing wave can be moved in one direction, and the bubbles having the action of cleaning the surface of the working electrode 11 can be moved in one direction, so that the entire surface of the working electrode 11 is washed. It is effective.
(Eighth Embodiment) Using the frequency modulation method, phase modulation method, and beat method described in each of the above embodiments, the combination of the frequency modulation method and the phase modulation method, the frequency modulation method is used. Union with the law Set Is also possible.
[0052]
FIG. 8 shows the acoustic wave standing wave section by the “combination method” in which the “frequency modulation method” described in the fourth embodiment and the “beat method” described in the seventh embodiment are combined. It is a figure explaining the change of a position (position where a bubble is caught). AC voltage waveforms V expressed by (Equation 29) to (Equation 30) obtained by frequency-modulating the electroacoustic transducers 16 and 15 in the same manner as (Equation 11). ₁ (T), V ₂ Drive by (t). For example, AC voltage waveform V ₁ (T), V ₂ The frequency f of (t) ₁ (T), f ₂ (T) is expressed by (Expression 22) to (Expression 23).
[0053]
[Expression 22]
f ₁ (T) = f _1min + (F _1max -F _1min ) (T / T) (Expression 22)
[0054]
[Expression 23]
f ₂ (T) = f _2min + (F _2max -F _2min ) (T / T) (Expression 23)
However, the periodic function f ₁ (T), f ₂ (T) has a period T, satisfies (Equation 24) to (Equation 27), and is between t = nT and t = (n + 1) T (n = 0, 1, 2,...), F ₁ (T), f ₂ (T) increases linearly monotonically and f ₂ (T) and f ₁ Considering the case where the difference (δf ′) from (t) is always constant, the difference δf ′ is given by (Equation 28).
[0055]
[Expression 24]
f ₁ (T = nT; n = 0, 1, 2,...) = F _1min (Starting frequency) (Equation 24)
[0056]
[Expression 25]
f ₁ (T → nT; n = 0, 1, 2,...) → f _1max (End point frequency) (Equation 25)
[0057]
[Equation 26]
f ₂ (T = nT; n = 0, 1, 2,...) = F _2min (Starting frequency) (Equation 26)
[0058]
[Expression 27]
f ₂ (T → nT; n = 0, 1, 2,...) → f _2max (End point frequency) (Expression 27)
[0059]
[Expression 28]

[0060]
[Expression 29]

[0061]
[30]

FIG. 8A shows the frequency f. ₁ Time change 82 of (t), frequency f ₂ A time change 81 of (t) and a difference δf′83 given by (Equation 28) are shown. FIG. 8B shows f. ₂ (T) and f ₁ Assuming that the difference (δf ′) from (t) is always constant, the electroacoustic transducers 16 and 15 are connected to the AC voltage waveform V expressed by (Expression 29) to (Expression 30). ₁ (T), V ₂ It is a figure which shows the state of the movement of the node of an acoustic wave when driving by (t). The vertical axis in FIG. 8B indicates the position of the node of the standing wave of the acoustic wave projected on the x-axis connecting the electroacoustic transducers 16 and 15, and the position of the electroacoustic transducer 16 is the origin. A dotted line 84 indicates the standing wave intermediate plane.
[0062]
A dotted line 85 and a dotted line 86 are respectively the average frequency f of the starting frequency given by (Equation 31) to (Equation 32). _Amin , Average frequency f of end point frequency _Amax Shows the moving path of the standing wave node of the acoustic wave in the “beat method”.
[0063]
[31]
f _Amin = (F _1min + F _2min ) (Equation 31)
[0064]
[Expression 32]
f _Amax = (F _1max + F _2max ) (Equation 32)
In the standing wave section, the mode that moves with the frequency change described in the fourth embodiment and the mode that moves by “beat” described in the seventh embodiment are combined and surrounded by a dotted line 85 and a dotted line 86. Move the area as indicated by the arrow. In this embodiment, the range in which bubbles move is changed by the “frequency modulation method” and the “beat method”, and the surface of the working electrode 11 can be cleaned over a wide range.
[0065]
(Ninth embodiment)
In the above embodiments, the electroacoustic transducers 16 and 15 are represented by the alternating voltage waveform V expressed by (Expression 1) to (Expression 2). ₁ (T), V ₂ Although the example driven by (t) was demonstrated, the electroacoustic transducers 16 and 15 can also be driven using the rectangular wave g shown to (Equation 33)-(Equation 34).
[0066]
[Expression 33]
V ₁ (T) = V ₀₁ g (2πf ₁ t + α ₁ (...)
[0067]
[Expression 34]
V ₂ (T) = V ₀₂ g (2πf ₂ t + α ₂ (... 34)
Here, n = 0, 1, 2,..., F is a frequency, and τ is a period, and a rectangular wave g is defined as (Equation 35).
[0068]
FIG. 9 is a diagram illustrating a rectangular wave g that drives the electroacoustic transducer.
[0069]
[Expression 35]

Similar to the second embodiment, voltage waveforms for driving the electroacoustic transducers 16 and 15 are expressed as V in (Equation 33) to (Equation 34). ₀₁ = V ₀₂ = V ₀ , F ₁ = F ₂ = F ₀ , Α ₁ = Α ₂ = Α, (Equation 36), and f ₀ By substituting f (t) of (Equation 4) into (Equation 37), the position of the node of the standing wave of the acoustic wave can be changed by the “frequency modulation method” of the third embodiment. For example, V ₀ , F ₀ V ₀ = 150V, f ₀ = 1 MHz.
[0070]
[Expression 36]
V ₁ (T) = V ₂ (T) = V ₀ g (2πf ₀ t + α) (Equation 36)
[0071]
[Expression 37]

In the same manner as described above, the voltage waveform for driving the electroacoustic transducers 16 and 15 in the fourth to eighth embodiments can be a rectangular wave g. That is, the voltage waveform for driving the electroacoustic transducers 16 and 15 is a rectangular wave g, and the “frequency modulation method” in the fourth embodiment, the “improved method of the frequency modulation method” in the fifth embodiment, According to the “phase modulation method” of the embodiment, the “beat method” of the seventh embodiment, and the “combination method” of the eighth embodiment, the position of the node of the standing wave of the acoustic wave (the bubble is captured) Can be changed). The voltage waveform for driving the electroacoustic transducers 16 and 15 is referred to (Equation 11) in the case of the “frequency modulation method” (Equation 38), and in the case of the “improved method of the frequency modulation method” (Equation 12). (Equation 14) referring to (Equation 14) (Equation 39) to (Equation 41), and in the case of the “phase modulation method”, (Equation 15) to (Equation 17) are referred to (Equation 42) to (Equation 44), Refer to (Equation 19) to (Equation 20) in the case of the “beat method” and (Equation 45) to (Equation 46) in the case of the “combination method” and refer to (Equation 29) to (Equation 30). (Equation 47) to (Equation 48).
[0072]
[Formula 38]

[0073]
[39]
V ₁ (T) = V ₀ g {2π [f ₀ + Δfsin (2πt / T)] t + α ₁ }} (Equation 39)
[0074]
[Formula 40]
V ₂ (T) = V ₀ g {2π [f ₀ + Δfsin (2πt / T)] t + α ₂ )} ... (Equation 40)
[0075]
[Expression 41]
α ₂ -Α ₁ = Βπ (Equation 41)
[0076]
[Expression 42]
V ₁ (T) = V ₀ g {2πf ₀ t + α ₁ (T)} (Expression 42)
[0077]
[Expression 43]
V ₂ (T) = V ₀ g {2πf ₀ t + α ₂ (T)} (Expression 43)
[0078]
(44)
α ₂ (T) -α ₁ (T) = 2πt / T (Equation 44)
[0079]
[Equation 45]
V ₁ (T) = V ₀ g (2πf ₀ t + α) (Equation 45)
[0080]
[Equation 46]
V ₂ (T) = V ₀ g {2π (f ₀ + Δf) t + α} (Equation 46)
[0081]
[Equation 47]

[0082]
[Formula 48]

The rectangular wave drive can be realized by periodically switching between two potentials, and when the electroacoustic transducers 16 and 15 are driven by the various wave modulation methods of this embodiment, they are realized by a simple circuit compared to the sine wave drive. In particular, the rectangular wave represented by (Equation 33) and (Equation 34) has a voltage V ₀₁ , V ₀₂ And a switching circuit that periodically switches between application of the voltage and ground, and the electroacoustic transducer can be driven with a simple circuit configuration.
[0083]
(Tenth embodiment)
In the present invention, in order to efficiently clean the inside of the flow cell, it is necessary to efficiently irradiate the acoustic wave to the flow cell channel of the flow-through detector.
[0084]
FIG. 10 is a diagram showing the configuration of the flow cell of the flow-through detector in the tenth embodiment of the present invention. The flow cell flow path of the flow-through detector of the present embodiment includes a cell portion 316 having an internal space of a predetermined volume and a solution flowing therethrough, and an upper plate 317 having a solution inlet 311 and an outlet 312. The solution is introduced from the inlet 311 and discharged from the outlet 312, and a flow cell channel is formed in the internal space of the cell portion 316. A part of the wall of the cell portion 316 is made of a polymer rubber 313, an electroacoustic transducer 314 is disposed on the outer surface side of the polymer rubber 313, and a magnet 315 that forms a magnetic field that holds magnetic fine particles below the cell portion 316. Is arranged. For example, a PZT piezoelectric element is used as the electroacoustic transducer 314.
[0085]
The portion of the polymer rubber 313 has a structure that can be removed from a part of the wall of the cell portion 316, and the electroacoustic transducer 314 can be easily replaced. In the example shown in FIG. 10, only one electroacoustic transducer 314 is used. However, a plurality of electroacoustic transducers 314 may be used to increase the efficiency of cleaning inside the flow cell. For example, a portion of the polymer rubber 313 is detachably disposed on a part of the opposing wall of the cell portion 316, and an electroacoustic transducer is disposed on each polymer rubber.
[0086]
As the frequency of the acoustic wave by the electroacoustic transducer 314 is higher, the cleaning efficiency is higher, and a frequency of 1 MHz or more is preferable. In the direction in which the acoustic wave is transmitted by the electroacoustic transducer 314, the polymer rubber 313 has two parallel surfaces. The distance between the two surfaces, that is, the thickness of the polymer rubber 313 is preferably an integral multiple of (1/4) the wavelength of the acoustic wave, so that the efficiency of acoustic wave irradiation into the flow cell is increased. .
[0087]
A polymer rubber 313 having acoustic characteristics similar to those of an aqueous solution is used to efficiently propagate acoustic waves from the electroacoustic transducer into the flow cell channel. That is, the polymer rubber 313 has a sound velocity of about 1500 m / sec, an acoustic impedance of 1.4 to 1.6 MRrays, and a polymer rubber having a small acoustic attenuation is used. As the polymer rubber 313, for example, isobutylene rubber (IR), natural rubber (NR), styrene / butadiene rubber (SBR), ethylene / propylene / diene copolymer (EPDM), and butadiene rubber (BR) are preferable, and the sound velocity is high. About 1550 m / sec, acoustic impedance is about 1.5 MRrays, and acoustic attenuation is 1.5 dB / cm or less (at 3 MHz). In addition, silicone rubber (FVMQ, MQ, PMQ, PVMQ, VMQ), fluorine rubber, polyurethane rubber, epichlorohydrin rubber, acrylic rubber, and the like can be used. In particular, fluororubber (a copolymer of propylene hexafluoride and vinylidene fluoride) has good chemical resistance and can be suitably used.
[0088]
In the configuration shown in FIG. 10, since the electroacoustic transducer is not in direct contact with the flow cell flow path, the electroacoustic transducer is not subject to erosion or denaturation by the solution, and heat generated during vibration of the electroacoustic transducer is not generated. There is a feature that it is difficult to propagate to the flow cell channel.
[0089]
Next, how to use the flow-through detector of this embodiment will be described. First, when a magnetic field is formed in the flow cell by the magnet 315 and a solution containing magnetic fine particles capturing the substance to be inspected in the sample is introduced from the inlet 311, the magnetic fine particles are held on the wall surface of the strong magnetic field region in the flow cell. The Next, the substance to be inspected captured by the magnetic fine particles is detected and quantitative analysis is performed. As this detection method, for example, there is a method of detecting luminescence by an electrochemiluminescence reaction using a ruthenium complex as a label.
[0090]
After the substance to be inspected is detected and quantitative analysis is performed, the magnetic field of the magnet 315 is erased. The magnetic field is erased by turning off the current when using an electromagnet as the magnet 15 and keeping the permanent magnet away from the flow cell channel when using a permanent magnet. After erasing the magnetic field, a cleaning solution is introduced from the inlet 311 and an acoustic wave from the electroacoustic transducer 314 is irradiated into the flow cell channel to clean the inside of the flow cell. As the cleaning solution, for example, a strong base solution such as potassium hydroxide or a hypochlorous acid aqueous solution can be suitably used. After washing in the flow cell, conditioning is performed with a phosphate buffer or the like, and the process proceeds to the next sample measurement.
[0091]
(Eleventh embodiment)
FIG. 11 is a diagram showing a flow cell of a flow-through type chemical analyzer utilizing an electrochemiluminescence reaction in an eleventh embodiment of the present invention. The flow cell has a PEEK (Poly-Ether-Ether-Ketone) lower substrate 321 on which a platinum flat plate electrode 211 is arranged, an inlet 222 and an outlet 223, and is made of acrylic on which a platinum wire electrode 221 is arranged. The upper substrate 322 and a fluororubber gasket 323 formed by punching a fluororubber flat plate with a mold to form a space of the flow cell channel 231 and a space in which PZT is disposed are overlapped. In the space where the PZT of the fluororubber gasket 323 is disposed, the PZT piezoelectric elements 241 and 242 are disposed to face each other. The resonance frequency of the piezoelectric element is 1 MHz.
[0092]
A solution containing a magnetic fine particle bound with a ruthenium complex which is one of electrochemiluminescent labels, a reducing agent used in an electrochemiluminescent reaction, and a sample is introduced into a flow cell, and the magnetic fine particle is attached to a plate electrode 211 with a magnet (not shown). Then, a voltage is applied to the line electrode 221 and the plate electrode 211 to induce an electrochemiluminescence reaction, and the resulting luminescence intensity is measured through an acrylic upper substrate 322 (the measurement result is S ₁ And). Next, while introducing a 0.1N potassium hydroxide aqueous solution as a cleaning solution, a 1 MHz sine wave having a predetermined voltage amplitude is applied to drive the piezoelectric element to generate an acoustic wave, and the magnetic fine particles in the flow cell Were removed by washing with a constant washing time.
[0093]
After washing, a solution containing only a reducing agent used in electrochemiluminescence is introduced into the flow cell, and a voltage is applied again to the line electrode 221 and the plate electrode 211 to induce an electrochemiluminescence reaction, and the resulting emission intensity Was measured via an acrylic upper substrate 322 (measurement result was S ₂ And). From the measurement results of the above experiment, the flow cell carryover (specimen contamination between different samples) C _O C _O = S ₂ / S ₁ And the effect of irradiating an acoustic wave into the flow cell via fluororubber was evaluated. The comparison experiment was carried out using a flow cell having the same thickness as the fluororubber flat plate instead of the fluororubber gasket 323, with the same experimental conditions. _O Asked.
[0094]
Figure 12 shows carryover C _O And PZT drive voltage amplitude (V _PP FIG. In FIG. 12, V _PP The point of = 0 is a case where the PZT is not driven and an acoustic wave is not irradiated into the flow cell. When irradiating acoustic waves into the flow cell through fluoro rubber, carry over C _O Is V _PP = 35, carry-over C when acoustic waves are not irradiated into the flow cell _O (V _PP = 0 / 1.5) and V _PP = 70, carry over C _O Is almost zero. However, when a flow cell using a PEEK plate is used instead of the fluororubber gasket 323 and an acoustic wave is irradiated into the flow cell through the PEEK, as shown by a point Δ in FIG. _O Is V _PP = 70, carry-over C when acoustic waves are not irradiated into the flow cell _O (V _PP = 0), and there was no effect of acoustic wave irradiation. In this embodiment, the trapping of bubbles generated at the node of the standing wave of the acoustic wave and the movement of the bubbles are not performed.
[0095]
(Twelfth embodiment)
In each of the above embodiments, the solution is always electrolyzed at the working electrode, bubbles are generated, the bubbles generated in the standing wave section of the acoustic wave are captured, and the bubbles are moved. Remove material present on the surface. However, there may be cases where the solution cannot be electrolyzed on the surface of the working electrode, or it may be necessary to remove substances present on the surface other than the surface on which the working electrode is disposed inside the flow cell. Further, in the flow cell shown in FIGS. 1 and 11, when the working electrode 11 is formed of a transparent electrode such as ITO or a deposited thin film such as platinum, electrolysis of the solution on the surface of the working electrode 11 is performed by the working electrode. 11 life may be significantly deteriorated.
[0096]
FIG. 13 is a diagram showing a schematic configuration of a flow cell of a flow-through detector in which an electrode for electrolysis that performs dedicated electrolysis of a solution is arranged in the twelfth embodiment of the present invention. As shown in FIG. 13, the electrode 101 for electrolysis is arranged on the bottom surface in the flow cell on the upstream side of the flow of the electrolyte solution in the flow cell, that is, on the side of the arrow 114 in the y direction where the electrolyte solution flows into the flow cell. To do. Needless to say, the electrode for electrolysis 101 may be arranged in the configuration shown in FIGS.
[0097]
The potential of the electrolysis electrode 101 with respect to the liquid phase potential is set to be equal to or higher than the electrolysis potential of water, and the aqueous solution is electrolyzed on the surface of the electrolysis electrode 101 to generate bubbles. Electroacoustic transducers 16 and 15 (arranged in the same manner as in FIG. 1 but not shown in FIG. 13) are driven to generate acoustic waves, and a standing wave node of acoustic waves is formed on the bottom surface in the flow cell. The bubbles generated at the electrode for electrolysis 101 are captured at the standing wave section of the acoustic wave, and the bubbles are moved on the bottom surface in the flow cell by the method of each embodiment described above, and the flow cell flow path is cleaned. Can be achieved more efficiently without deteriorating the working electrode 11. Further, the length of the electroacoustic transducers 16 and 15 in the y direction shown in FIG. 13 can be increased to clean a wider area of the bottom surface in the flow cell.
[0098]
(Thirteenth embodiment)
FIG. 14 is a diagram showing a schematic configuration of an electrochemiluminescence (hereinafter abbreviated as ECL) immunoassay device of a thirteenth embodiment of the present invention. In this embodiment, the magnetic fine particles are removed by washing from the working electrode of the flow-through type ECL detection cell and the bottom surface of the flow cell channel. The apparatus of this embodiment includes a sample container 1 for storing a sample, a reaction reagent container 2 for storing a reaction reagent, a cleaning reagent container 3 for storing a cleaning reagent, a fractionator 4, and two electroacoustic transducers. A flow-through type ECL detection cell 5 having 15 and 16, a magnet 6, a photodetector 7, a pump 8, a potentiostat 14, a drive control unit (circuit) 17, and a control unit 9. Is done.
[0099]
FIG. 15 is a diagram illustrating the configuration of the sample solution. As shown in FIG. 15, the sample solution has a magnetic fine particle (diameter 2.8 μm) 123 that has captured the test target substance 121 by antigen-antibody binding, and a reaction having an electrochemiluminescent label 122 that binds to the captured test target substance 121. It is a suspension containing a product, a free electrochemiluminescent label 122, and free magnetic fine particles 123 that have not captured the test substance 121. The reaction reagent is a phosphate buffer containing tripropylamine, which is a reducing agent used in the electrochemiluminescence reaction, and the cleaning reagent is an aqueous potassium hydroxide solution (concentration 0.1 N). In this example, a suspension of magnetic fine particles having a predetermined amount of ruthenium (II) tribipyridyl complex label immobilized on the surface in advance was used as a comparative sample for confirming the effect of the invention. These various solutions flow into the ECL detection cell 5 from the direction of the arrow 114, pass through the flow cell flow path formed by the cell lower substrate 111, the intermediate substrate 112, and the cell upper substrate 113 and flow out in the direction of the arrow 115. To do.
[0100]
The electroacoustic transducers 15 and 16 are each independently connected to the drive control unit 17 and are independently controlled and driven. The counter electrodes 13-1 and 13-2, the electrolysis electrode 101, the working electrode 11, and the reference electrode 12 of the ECL detection cell 5 are connected to the potentiostat 14. The control unit 9 controls the fractionator 4, the magnet 6, the potentiostat 14, the pump 8, and the drive control unit 17 based on the measurement sequence, and detects the light emitted from the ECL detection cell 5 by the photodetector 7. Record the results.
[0101]
The ECL detection cell 5 of the present embodiment is almost the same as the configuration shown in FIG. The cell lower substrate 111 is PEEK with good solution resistance. Electrolysis electrode 101 and working electrode 11 are platinum electrodes. The on-cell substrate 113 on which the counter electrodes 13-1 and 13-2 are arranged is a light transmissive acrylic plate. The intermediate substrate 112 including the intermediate substrate member 112-1 on which the electroacoustic transducer 15 is disposed and the intermediate substrate member 112-2 on which the electroacoustic transducer 16 is disposed is a fluororubber plate having a thickness of 0.5 mm. The intermediate substrate members 112-1 and 112-2 are formed by laser cutting a fluororubber flat plate into a desired shape to form a flow cell flow path and used as a gasket.
[0102]
The electroacoustic transducers 15 and 16 are PZTs having a rectangular parallelepiped shape, and electrodes are provided on opposing surfaces. When an AC voltage is applied between these electrodes, the electroacoustic transducer vibrates in the direction between the electrodes, and an acoustic wave is generated. The thickness between the electrodes determines the resonance frequency of the electroacoustic transducer, and the resonance frequencies of the electroacoustic transducers 15 and 16 are both about 1.0 MHz. The length of one side perpendicular to the polarization of PZT was made less than the thickness of the gasket, and the length of the other side perpendicular to the polarization was made longer than the length of the working electrode 11. That is, as shown in FIG. 14, the length of the electroacoustic transducers 15 and 16 in the direction connecting the arrow 114 and the arrow 115 is equal to or longer than the length of the working electrode 11 in the direction connecting the arrow 114 and the arrow 115. .
[0103]
Next, the operation of the apparatus of this embodiment will be described in detail. The operation of the apparatus of this example is as follows: (1) introduction of a sample into the ECL detection cell 5, (2) introduction of a reaction reagent into the ECL detection cell 5, (3) occurrence of electrochemiluminescence reaction and electrochemiluminescence. And (4) cleaning the ECL detection cell 5 and (5) regenerating the working electrode 11.
[0104]
Of these steps, steps (1), (2), (3), and (5) are performed in the same manner as in the prior art. In step (1), the sample solution is introduced in a state where the magnet 6 is brought close to the working electrode of the ECL detection cell 5, and the magnetic fine particles 123 are held inside the ECL detection cell 5. In step (2), a reaction reagent (a phosphate buffer containing tripropylamine as a drug reducing agent) is flowed into the five flow cell channels of the ECL detection cell, and substances other than the magnetic microparticles 123 are removed from the ECL detection cell 5. The magnetic fine particles 123 surrounded by the reaction reagent remain in the flow cell channel. In step (3), the magnet 6 is separated from the ECL detection cell 5, the potential between the working electrode 11 and the liquid phase in the flow cell flow path is set as an electrochemiluminescence reaction potential, and an electrochemiluminescence reaction is caused. The light intensity of electrochemiluminescence generated on the surface of the working electrode 11 is measured by the photodetector 7. The emission intensity is proportional to the amount of the electrochemiluminescent label 122 for labeling the test target substance present in the sample solution, that is, the amount of the test target substance. In step (5), the reaction reagent 11 is reintroduced to regenerate the working electrode 11.
[0105]
In step (4) in the prior art, a cleaning reagent is introduced into the flow cell flow path of the ECL detection cell 5, and at the same time, the potential between the working electrode 11 and the liquid phase of the flow cell flow path is higher than the electrolysis potential of water. The bubbles are generated on the surface of the working electrode 11 by setting, and the substance on the surface of the working electrode is removed by the action of the bubbles and the action of the flow of the cleaning reagent.
[0106]
In step (4) in the apparatus of this embodiment, the magnetic fine particles present on the surface of the working electrode 11 are removed to the outside of the ECL detection cell 5. In the washing step of the present invention, washing is performed by adding new actions to the action of bubbles generated by electrolysis of water and the action of the flow of the washing reagent in the step (4) of the prior art. That is, as described in the third to ninth embodiments described above, an AC or rectangular wave voltage waveform is used, and the electroacoustic transducers 16 and 15 are voltage-driven by various modulation methods to generate sound. The position of the node of the standing wave wave (the position where the bubbles are trapped) is changed in a wide range, the bubbles are captured in a wide range, and a physical force is applied to a wide surface including the entire surface of the working electrode 11. Thus, a wide surface including the entire surface of the working electrode 11 is efficiently cleaned, and the cleaning performance is improved. The acoustic wave is irradiated into the flow cell via the polymer rubber (fluororubber) to further improve the cleaning efficiency.
[0107]
In this example, the cleaning performance of the cleaning process was compared under the following four types of experimental conditions. In the present embodiment, when bubbles are generated by electrolysis, the working electrode 11 is used instead of the electrolysis electrode 101 shown in FIG. 11, and the steps (1), (2), (3), and ( 5) was performed under the same conditions as in the prior art.
[0108]
Experiment-1: Experiment using process (4) in the prior art.
[0109]
Experiment-2: Under the conditions described in the third embodiment of the present invention (FIG. 3), two electroacoustic transducers are driven by the “frequency modulation method” in which the frequency is changed sinusoidally and periodically. Experiment using step (4) of changing the position of a wave standing wave node.
[0110]
Experiment-3: Two electroacoustic transducers are driven by a “frequency modulation method” in which the frequency is linearly and periodically changed under the conditions described in FIG. 5 of the fourth embodiment of the present invention. Experiment using step (4) of changing the position of a wave standing wave node.
[0111]
Experiment-4: Experiment using the step (4) in which the “frequency modulation method” is not adopted in the experiment-2 (therefore, the movement of the standing wave node of the acoustic wave does not occur)).
[0112]
The evaluation of the cleaning performance is performed by performing steps (1), (2), and (3) using the sample solution as the measurement sample, and the emission intensity S ₁ , And the emission intensity S ₁ After the measurement, Step (4) corresponding to Experiment-1, Experiment-2, and Experiment-3 is performed, and then Step (5) is performed to newly add to the flow cell flow path of the ECL detection cell 5. Luminescence intensity S due to components remaining in the ECL detection cell 5 without introducing the sample solution ₂ 'And measure flow cell carryover (specimen contamination between different samples) C _O C _O = S ₂ '/ S ₁ The carry-over in various cleaning methods was compared.
[0113]
FIG. 16 shows the cleaning time and carryover C according to various cleaning methods. _O It is a figure which shows the comparison result of. The horizontal axis in FIG. 16 is the cleaning time, and T ₀ Is the cleaning time in the prior art. In FIG. 16, the plot 131 marked with ● is a carry-over C in the cleaning process (prior art) in Experiment-1. _O , □ mark plot 132 shows carry-over C in the cleaning process of Experiment-2. _O , ○ plot 133 indicates carry-over C in the cleaning process of Experiment-3. _O , Δ marked plot 134 shows carry-over C in the cleaning step of Experiment-4. _O Indicates. The cleaning time shown in FIG. 16 is different from the cleaning time when the result of FIG. 12 is obtained, and the dimensions and shape of the flow cell used when obtaining the results of FIG. 16 and FIG. 12 are different.
[0114]
From the results shown in FIG. 16, in Experiment-2 and Experiment-3, the cleaning time is the cleaning time T in the prior art. ₀ Carry over C _O Is about 1/3 of the conventional technology, and the cleaning time is the same as that of the conventional technology. ₀ Carryover C when 1/2 of _O Is about 1/8 of the conventional technology, and in Experiment-2 and Experiment-3, the cleaning time is set to the cleaning time T in the conventional technology. ₀ Carryover C, both at the same time as ½ time _O Are approximately the same, and in Experiment-2 and Experiment-3, the cleaning time can be shortened. Further, comparing the plot 134 with the plots 132 and 133, the movement of the standing wave node of the acoustic wave greatly contributes to the improvement of the cleaning performance, and the carryover can be reduced in a short time. It is clear that
[0115]
【The invention's effect】
According to the present invention, the position of a node of a standing wave of acoustic waves (position where bubbles are trapped) is widened by using an AC or rectangular wave voltage waveform and driving the electroacoustic transducer with voltage of various modulation methods. By changing the range, air bubbles are captured in a wide range, and a physical force is applied to a wide surface including the entire surface of the working electrode, so that the wide surface including the entire surface of the working electrode is efficiently cleaned. Can be improved. Irradiation of acoustic waves into the flow cell via polymer rubber (fluoro rubber) further improves the cleaning efficiency.
[0116]
In particular, it is possible to improve the cleaning efficiency of the flow cell of the chemical analyzer that performs detection (measurement) by the flow-through method after capturing the test target substance using magnetic fine particles and the electrochemiluminescence immunoanalyzer, and shorten the cleaning time. The analysis accuracy can be improved, the analysis time can be shortened, and the total amount of the cleaning solution can be reduced, so that the measurement throughput can be improved and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a flow-through detector according to a first embodiment of the present invention.
FIG. 2 is a diagram for explaining a state of a standing wave formed in a flow cell channel in the second embodiment of the present invention.
FIG. 3 is a diagram for explaining a change in the position of a node of a standing wave of an acoustic wave by a “frequency modulation method” in the third embodiment of the present invention.
FIG. 4 is a diagram for explaining details of a change in position of a node of a standing wave of an acoustic wave in a third embodiment of the present invention.
FIG. 5 is a diagram for explaining a change in the position of a node of a standing wave of an acoustic wave by a “frequency modulation method” in the fourth embodiment of the present invention.
FIG. 6 is a view for explaining that the spatial distribution of standing wave nodes is arbitrarily changed by the “improved frequency modulation method” in the fifth embodiment of the present invention.
FIG. 7 is a diagram for explaining a change in the position of a node of a standing wave of an acoustic wave by a “phase modulation method” in the sixth embodiment of the present invention.
FIG. 8 is a diagram for explaining a change in the position of a node of a standing wave of acoustic waves by the “combination method” in the eighth embodiment of the present invention.
FIG. 9 is a diagram showing a rectangular wave for driving an electroacoustic transducer in a ninth embodiment of the present invention.
FIG. 10 is a diagram showing the configuration of a flow cell of a flow-through type detector in a tenth embodiment of the present invention.
FIG. 11 is a view showing a flow cell of a flow-through type chemical analyzer using an electrochemiluminescence reaction in an eleventh embodiment of the present invention.
FIG. 12 shows carryover C in the eleventh embodiment of the present invention. _O And PZT drive voltage amplitude (V _PP FIG.
FIG. 13 is a diagram showing a schematic configuration of a flow cell of a flow-through type detector in which an electrode dedicated for electrolysis of a solution is arranged in a twelfth embodiment of the present invention.
FIG. 14 is a diagram showing a schematic configuration of an electrochemiluminescence immunoanalyzer in a thirteenth embodiment of the present invention.
FIG. 15 is a view for explaining the configuration of a sample solution in a thirteenth embodiment of the present invention.
FIG. 16 shows the cleaning time and carry-over C according to various cleaning methods in the thirteenth embodiment of the present invention. _O FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sample container, 2 ... Reaction reagent container, 3 ... Cleaning reagent container, 4 ... Sorter, 5 ... Flow-through type ECL detection cell, 6 ... Magnet, 7 ... Photo detector, 8 ... Pump, 9 ... Control 11, working electrode, 12 reference electrode, 13-1, 13-2 counter electrode, 14 potentiostat, 15 electroacoustic transducer, 16 electroacoustic transducer, 17 drive control unit, 22 -1, 22-2 ... standing wave, 23-1, 23-2, 23-3, 23-4 ... node of standing wave, 24 ... distance between adjacent nodes of standing wave, 25 ... constant The region of the node of the standing wave and the region near the surface of the working electrode, 26 ... the flow direction of the solution in the flow cell, 61 ... the position of the node of the standing wave of the acoustic wave when there is no phase difference, 62 ... the phase difference The position of the node of the standing wave of the acoustic wave, 63 ... the moving distance of the position of the node of the standing wave of the acoustic wave, 64 ... the intermediate plane of the standing wave, 1 ... direction of movement of the nodes of the standing wave, 81 ... frequency f ₂ Time change of (t), 82 ... frequency f ₁ Time change of (t), 83 ... frequency f ₂ (T) and f ₁ Difference from (t), 84 ... Standing wave intermediate plane, 85, 86 ... Moving path of standing wave node of acoustic wave in "beat method", 101 ... Electrolysis electrode, 111 ... Sub-cell substrate, 112-1, 112-2 ... Intermediate substrate member, 112 ... Intermediate substrate, 113 ... Cell substrate, 121 ... Substance to be inspected, 122 ... Electrochemiluminescence label, 123 ... Magnetic fine particles, 131 ... In the cleaning process of Experiment-1 132 ... Carryover in the cleaning process of Experiment-2, 133 ... Carryover in the cleaning process of Experiment-3, 134 ... Carryover in the cleaning process of Experiment-4, 211 ... Flat plate electrode, 221 ... Wire electrode, 222 ... inlet, 223 ... outlet, 231 ... flow cell flow path, 241, 242 ... piezoelectric element, 311 ... inlet, 312 ... outlet, 313 ... polymer rubber, 314 ... electroacoustic transducer, 3 5 ... Magnets, 316 ... Cell part, 317 ... Upper plate, 321 ... Lower substrate, 322 ... Upper substrate, 323 ... Fluoro rubber gasket, 412, 422, 432 ... Standing wave intermediate surface, 413, 414, 423, 424, 433: Position of the bubble trapped in the node of the standing wave, 443, 444: Range of movement of the bubble trapped in the node of the standing wave.

Claims (4)

A cell through which the solution flows;
Means for generating bubbles in the solution; an electroacoustic transducer;
A flow-through type apparatus comprising: control means for performing control to change the position of the bubble by changing the position of a node of a standing wave of the acoustic wave emitted from the electroacoustic transducer.   The flow-through apparatus according to claim 1, wherein the control unit controls a frequency of an AC voltage that drives the electroacoustic transducer or a phase difference between the AC voltages. A cell through which the solution flows;
Means for generating bubbles in the solution;
Means for retaining particles in the cell;
An electroacoustic transducer;
A flow-through type apparatus comprising: control means for performing control to change the position of the bubble by changing the position of a node of a standing wave of the acoustic wave emitted from the electroacoustic transducer.   4. The flow-through type apparatus according to claim 3, wherein the means for holding the particles has a flat portion having electrodes, and the electrodes electrolyze the solution to generate bubbles.

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