JP2012141263A - Micro object amount measurement apparatus and micro object amount measurement method - Google Patents
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
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Abstract
Description
本発明は、微小物体量測定装置および微小物体量測定方法に関するものである。 The present invention relates to a minute object amount measuring apparatus and a minute object amount measuring method.
水中に存在する微小物体、具体的には大きさ０．１μｍから１０μｍ程度の細菌やプラスチック粒子の量を測定する方法として、電気抵抗法を用いた微小物体の測定方法が提案されている。 As a method for measuring the amount of minute objects existing in water, specifically bacteria and plastic particles having a size of about 0.1 μm to 10 μm, a method of measuring a minute object using an electrical resistance method has been proposed.
図７は、特許文献１に開示されているマイクロ血球カウンタ１００の概略斜視図である。マイクロ血球カウンタ１００は、流路１０２の途中にアパ−チャ１０２Ｃを形成し、このアパーチャ１０２Ｃの両側の流路１０２Ａ、１０２Ｂにそれぞれ電極１０３、１０４を設け、検体血液を一方の流路１０２Ａ側からアパーチャ１０２Ｃを経て他方の流路１０２Ｂ側に移動させ、検体血液が前記アパ−チャ１０２Ｃを通過するときに生ずるインピーダンス変化を両電極１０３、１０４によって検出するものである。 FIG. 7 is a schematic perspective view of the micro blood cell counter 100 disclosed in Patent Document 1. As shown in FIG. In the micro blood cell counter 100, an aperture 102C is formed in the middle of the flow path 102, electrodes 103 and 104 are provided on the flow paths 102A and 102B on both sides of the aperture 102C, respectively, and sample blood is supplied from one flow path 102A side. It is moved to the other channel 102B side through the aperture 102C, and the impedance change that occurs when the sample blood passes through the aperture 102C is detected by both electrodes 103 and 104.
特許文献１のマイクロ血球カウンタ１００は、各電極１０３、１０４を各流路１０２Ａ、１０２Ｂの底部１０２ａ、１０２ｂに設けるとともに、各電極１０３、１０４にそれぞれ接続された電極リード部１０５、１０６を流路底部１０２ａ、１０２ｂと同じレベル位置になるように形成することにより、電極リード部１０５、１０６が途中で断線したり、検体血液の詰まりが生じたりすることを防止している。 In the micro blood cell counter 100 of Patent Document 1, the electrodes 103 and 104 are provided on the bottom portions 102a and 102b of the flow paths 102A and 102B, and the electrode lead portions 105 and 106 connected to the electrodes 103 and 104 are flow paths. By forming so that it may become the same level position as bottom part 102a, 102b, it is preventing that the electrode lead part 105,106 breaks in the middle or clogging of the sample blood arises.
しかしながら、従来の微小物体の測定装置には以下のような問題があった。すなわち、特許文献１のマイクロ血球カウンタでは、測定用の電極が流路の底部に備えられていることから、検体液に含有されている粒子が流路の深さ方向のどの位置を通過するかによって電流密度が異なるため、出力値にばらつきが生じ、測定精度が低下するという問題があった。 However, the conventional apparatus for measuring minute objects has the following problems. That is, in the micro blood cell counter of Patent Document 1, since the measurement electrode is provided at the bottom of the flow path, which position in the depth direction of the flow path the particles contained in the sample liquid pass through. Since the current density differs depending on the output, there is a problem in that the output value varies and the measurement accuracy decreases.
上記の問題に鑑み、本発明は、出力値のばらつきを低減して測定精度を向上させた微小物体量測定装置を提供することを目的とする。 In view of the above problems, an object of the present invention is to provide a minute object amount measuring apparatus in which variation in output value is reduced and measurement accuracy is improved.
微小物体を含む液体をフローセルに流し、フローセルに備えられたセンサ部で微小物体の量を測定する微小物体量測定装置であって、センサ部の上流側に、微小物体をセンサ部の近傍に泳動させる微小物体泳動手段を備える。 A device for measuring the amount of a minute object by flowing a liquid containing a minute object into a flow cell and measuring the amount of the minute object with a sensor unit provided in the flow cell. The minute object is migrated upstream of the sensor unit and in the vicinity of the sensor unit. There is provided a micro object migration means.
本発明の微小物体量測定装置によれば、検体液中の微小物体をセンサ部の近傍に泳動させ、センサ部の表面近傍を通過させるので、出力値のばらつきが低減され、測定精度を向上させることができる。 According to the minute object amount measuring apparatus of the present invention, the minute object in the sample liquid is migrated to the vicinity of the sensor unit and passes through the vicinity of the surface of the sensor unit, so that variations in output values are reduced and measurement accuracy is improved. be able to.
以下、本発明の実施形態である微小物体量測定装置および微小物体量測定方法について、以下に詳細に説明する。 Hereinafter, a minute object amount measuring apparatus and a minute object amount measuring method according to embodiments of the present invention will be described in detail.
図１は、実施例１である本発明の微小物体量検出装置を示す上方断面図であり、図２は、その側方断面図である。微小物体量検出装置１は、図１および図２に示すように、上面基板２と底面基板３で構成されるフローセル４を備え、フローセル４の内部には検体液を流すことができる流路５が設けられている。上面基板２と底面基板３には、加工が容易であるガラス基板やシリコン基板等の板状部材が用いられている。 FIG. 1 is an upper cross-sectional view showing a minute object amount detection device of the present invention which is Embodiment 1, and FIG. 2 is a side cross-sectional view thereof. As shown in FIGS. 1 and 2, the minute object amount detection device 1 includes a flow cell 4 including a top substrate 2 and a bottom substrate 3, and a flow channel 5 through which a sample liquid can flow inside the flow cell 4. Is provided. The top substrate 2 and the bottom substrate 3 are made of plate-like members such as glass substrates and silicon substrates that can be easily processed.
上面基板２には、図１に示すように、検体液を流す流路５と、電解液を流す調整路６が形成されている。流路５と調整路６の深さは、検体液に含まれる微小物体の大きさにもよるが約３０〜２００μｍ程度の深さで形成される。 As shown in FIG. 1, the upper surface substrate 2 is formed with a flow path 5 through which the sample liquid flows and an adjustment path 6 through which the electrolytic solution flows. The depth of the flow path 5 and the adjustment path 6 is formed to a depth of about 30 to 200 μm, although it depends on the size of the minute object contained in the sample liquid.
フローセル４は、上面基板２の流路５と調整路６が設けられた面に、底面基板３が貼り合わされて構成される。図１に示すフローセル４は、流路５において検体液が左から右に流れるように構成されており、入口側には図示しない検体液の供給部が接続され、出口側には図示しない検体液の回収部が接続されている。 The flow cell 4 is configured by bonding the bottom substrate 3 to the surface of the top substrate 2 on which the flow path 5 and the adjustment path 6 are provided. The flow cell 4 shown in FIG. 1 is configured such that the sample liquid flows from the left to the right in the flow path 5, a sample liquid supply unit (not shown) is connected to the inlet side, and the sample liquid (not shown) is connected to the outlet side. The recovery unit is connected.
調整路６は、フローセル４の入口側で流路５と合流するように設けられており、外部に設けられた電解液タンク１１と流路５とを接続している。そして、調整路６の途中に設けられたバルブ１０の開閉により、流路５を流れる検体液に一定量の電解液を加えて電気伝導度（インピーダンス）を調整できるようになっている。 The adjustment path 6 is provided so as to merge with the flow path 5 on the inlet side of the flow cell 4, and connects the electrolyte tank 11 provided outside and the flow path 5. The electrical conductivity (impedance) can be adjusted by adding a certain amount of electrolyte to the sample liquid flowing through the flow path 5 by opening and closing the valve 10 provided in the middle of the adjustment path 6.
流路５と対向する底面基板３側の流路面には、出口側にセンサ部として測定電極８が設けられており、このセンサ部の上流側には、微小物体泳動手段として検体液中の微小物体を測定電極８の近傍に泳動させる泳動電極９が設けられている。 A measurement electrode 8 is provided as a sensor unit on the outlet side on the channel surface on the bottom substrate 3 side facing the channel 5, and a minute object in the sample liquid is used as a micro object migration means on the upstream side of the sensor unit. A migration electrode 9 for migrating an object in the vicinity of the measurement electrode 8 is provided.
センサ部の測定電極８は、図１に示すように、流路５を横切るように形成された一対の平板状電極からなり、検体液の流れる方向に所定の間隔を有して並設されている。 As shown in FIG. 1, the measurement electrode 8 of the sensor unit is composed of a pair of flat electrodes formed so as to cross the flow path 5, and is arranged in parallel with a predetermined interval in the direction in which the sample liquid flows. Yes.
測定電極８は、定電流源１２と電圧計１３に接続されており、電圧計１３は信号演算手段１４と接続されている。センサ部は、測定電極８間に定電流を印加し、検体液のインピーダンス値と定電流値との積となる電圧を電圧計１３で測定する。 The measurement electrode 8 is connected to a constant current source 12 and a voltmeter 13, and the voltmeter 13 is connected to a signal calculation means 14. The sensor unit applies a constant current between the measurement electrodes 8, and measures a voltage that is a product of the impedance value and the constant current value of the sample liquid with the voltmeter 13.
微小物体泳動手段の泳動電極９は、一対の櫛歯状の電極が櫛部を対向させて、流路５の両側部に配置されている。泳動電極９は、電圧源１５と電流計１６に接続されている。また、圧源１５と電流計１６は制御手段１７に接続されている。 The migration electrode 9 of the minute object migration means is arranged on both sides of the flow path 5 with a pair of comb-like electrodes facing each other. The electrophoresis electrode 9 is connected to a voltage source 15 and an ammeter 16. The pressure source 15 and the ammeter 16 are connected to the control means 17.
泳動電極９は、図２の側方断面図に示すように、検体液中の微小物体の泳動軌跡を測定電極８が設けられた底面基板３の流路面に引き寄せる電場を発生させるものである。微小物体が底面基板３の流路面に引き寄せられ易くするため、泳動電極９は流路５に沿ってできるだけ長く設けて、微小物体が泳動電極９を通過する区間を延ばすことが望ましい。 As shown in the side sectional view of FIG. 2, the migration electrode 9 generates an electric field that draws the migration trajectory of the minute object in the sample liquid to the flow path surface of the bottom substrate 3 provided with the measurement electrode 8. In order to make it easy for a minute object to be attracted to the flow path surface of the bottom substrate 3, it is desirable that the migration electrode 9 be provided as long as possible along the flow path 5 to extend a section through which the minute object passes the migration electrode 9.
測定電極８と泳動電極９の材質は、電気化学的に安定な白金が好ましいが、ＡｕやＡｌ電極に保護膜を設けた構成としてもよい。電極の厚みは、検出感度や密着性の観点から３００ｎｍ程度とするのが好ましい。測定電極８と泳動電極９は、真空蒸着やスパッタ法などを用い基板上に同時に形成することができる。 The material of the measurement electrode 8 and the migration electrode 9 is preferably electrochemically stable platinum, but may be configured such that a protective film is provided on an Au or Al electrode. The thickness of the electrode is preferably about 300 nm from the viewpoint of detection sensitivity and adhesion. The measurement electrode 8 and the migration electrode 9 can be simultaneously formed on the substrate using vacuum deposition or sputtering.
なお、測定電極８と泳動電極９は流路５の途中に設けられるが、底面基板３の流路面に平板状に形成されているため、検体液の流れを妨げることはなく、流路５において検体液中の微小物体を目詰まりさせることは生じない。 Although the measurement electrode 8 and the migration electrode 9 are provided in the middle of the flow path 5, the measurement electrode 8 and the migration electrode 9 are formed in a flat plate shape on the flow path surface of the bottom substrate 3. It does not cause clogging of minute objects in the sample liquid.
また、測定電極８と泳動電極９は上面基板２側の流路面に設けられてもよい。
（実施例１の処理フロー）
続いて、本発明の微小物体量測定装置１を用いた微小物体の測定方法について説明する。図３は、本発明の微小物体量測定方法を説明するための処理フロー図である。
Further, the measurement electrode 8 and the migration electrode 9 may be provided on the flow path surface on the upper substrate 2 side.
(Processing flow of Example 1)
Next, a method for measuring a minute object using the minute object amount measuring apparatus 1 of the present invention will be described. FIG. 3 is a process flow diagram for explaining the minute object amount measuring method of the present invention.
まず初めに、フローセル４に供給部から微小物体を含む検体液が導入される。検体液は、流路５に沿って、微小物体泳動手段である泳動電極９と、センサ部である測定電極８に順次流れる。 First, a sample liquid containing a minute object is introduced into the flow cell 4 from the supply unit. The sample liquid sequentially flows along the flow path 5 to the migration electrode 9 that is a minute object migration means and the measurement electrode 8 that is a sensor unit.
次に、検体液を流した状態で泳動電極９間に直流電圧が印加され、検体液に流れる電流値が測定される。この電圧値と電流値は制御手段１７に送信され、検体液のインピーダンスが算出される。ここで、検体液のインピーダンスが、次段の測定電極８で信号電圧として測定可能な範囲を超える場合、制御手段１７から調整路６のバルブ１０を開閉する指令が送信され、電解液タンク１１から一定量の電解液が流路５に流入され検体液のインピーダンスが調整される。このインピーダンスの調整作業は、センサ部の測定電極８に定電流を印加したとき、信号電圧として測定可能なインピーダンスとなるまで繰り返される。 Next, a direct current voltage is applied between the migration electrodes 9 in a state in which the sample liquid is flowed, and the current value flowing through the sample liquid is measured. The voltage value and the current value are transmitted to the control means 17, and the impedance of the sample liquid is calculated. Here, when the impedance of the sample liquid exceeds a range that can be measured as a signal voltage at the measurement electrode 8 at the next stage, a command to open and close the valve 10 of the adjustment path 6 is transmitted from the control means 17, and the electrolyte tank 11 A certain amount of electrolytic solution flows into the flow path 5 to adjust the impedance of the sample liquid. This impedance adjustment operation is repeated until a constant current is applied to the measurement electrode 8 of the sensor unit until the impedance becomes measurable as a signal voltage.
検体液のインピーダンスが調整された後、制御手段１７は、検体液のインピーダンスに応じて微小物体を検出するために用いる閾値を決定し、信号演算手段１４に送信する。 After the impedance of the sample liquid is adjusted, the control unit 17 determines a threshold value used for detecting a minute object according to the impedance of the sample liquid, and transmits the threshold value to the signal calculation unit 14.
制御手段１７は、電圧源１５を制御して、泳動電極９間に検体液のインピーダンスに応じた交流電圧を印加する。泳動電極９間には、交流電界が発生し、検体液中の微小物体が泳動電極９間に引き寄せられる正の誘電泳動力が発生する。微小物体に働く誘電泳動力は、検体液の流れの力とつりあうように電界の強度が調整される。具体的には、微小物体が泳動電極９間に引き寄せられるが補足されるには至らず、検体液の流れに乗ってセンサ部に移動できる程度の誘電泳動力である。例えば、泳動電極９間に印加される電圧値、周波数は、１〜１００Ｖ、１０〜１００ｋＨｚ程度に設定される。 The control means 17 controls the voltage source 15 to apply an AC voltage corresponding to the impedance of the sample liquid between the migration electrodes 9. An alternating electric field is generated between the migration electrodes 9, and a positive dielectrophoretic force is generated that attracts minute objects in the sample liquid between the migration electrodes 9. The intensity of the electric field is adjusted so that the dielectrophoretic force acting on the minute object is balanced with the flow force of the sample liquid. Specifically, the dielectrophoretic force is such that a minute object is attracted between the migrating electrodes 9 but is not supplemented and can be moved to the sensor unit along the flow of the sample liquid. For example, the voltage value and frequency applied between the migration electrodes 9 are set to about 1 to 100 V and about 10 to 100 kHz.
微小物体は、泳動電極９を通過する間に、泳動電極９が設けられた底面基板３の流路面に引き寄せられながら、同じ底面基板３の流路面に設けられた次段の測定電極８の表面近傍に流れていく。 While passing through the migration electrode 9, the minute object is drawn to the flow path surface of the bottom substrate 3 on which the migration electrode 9 is provided, and the surface of the next-stage measurement electrode 8 provided on the flow path surface of the same bottom substrate 3. It flows in the vicinity.
測定電極８間には定電流源１２から検体液のインピーダンスに応じた定電流が印加されており、インピーダンス値と定電流値との積による電圧が電圧計１３に検出される。ここで、検体液中に微小物体が含まれていると、検体液のインピーダンスが変化し、パルス電圧となって検出される。 A constant current according to the impedance of the sample liquid is applied from the constant current source 12 between the measurement electrodes 8, and a voltage resulting from the product of the impedance value and the constant current value is detected by the voltmeter 13. Here, when a minute object is contained in the sample liquid, the impedance of the sample liquid changes and is detected as a pulse voltage.
信号演算手段１４は、電圧計１３で検出されたパルス電圧と閾値を比較し、閾値を超えるパルス電圧の数をカウントする。パルス電圧のカウントは、設定された測定時間内に亘り行われ、測定後、信号演算手段１４で、検体液の流量とパルス電圧のカウント数から微小物体の濃度（個／ｍｌ）が算出される。 The signal calculation means 14 compares the pulse voltage detected by the voltmeter 13 with a threshold value, and counts the number of pulse voltages exceeding the threshold value. The pulse voltage is counted over the set measurement time, and after the measurement, the signal calculation means 14 calculates the concentration (number / ml) of the minute object from the flow rate of the sample liquid and the count number of the pulse voltage. .
以上、説明したように、本発明の微小物体量測定装置１によれば、センサ部の上流側に、誘電泳動力によって微小物体をセンサ部の近傍に泳動させる微小物体泳動手段を備えており、微小物体の泳動軌跡がセンサ部の測定電極８の表面近傍を通過するように制御され、微小物体が測定電極８上を通過するときに、深さ方向でのばらつきが抑制されるため、微小物体の測定精度を向上することができる。 As described above, according to the minute object amount measuring apparatus 1 of the present invention, the minute object migration means for migrating the minute object to the vicinity of the sensor unit by the dielectrophoretic force is provided on the upstream side of the sensor unit. Since the migration trajectory of the minute object is controlled so as to pass near the surface of the measurement electrode 8 of the sensor unit, and when the minute object passes over the measurement electrode 8, variation in the depth direction is suppressed. The measurement accuracy can be improved.
なお、測定電極８と泳動電極９が底面基板３側の流路面に設けられた微小物体量測定装置１で説明したが、測定電極８と泳動電極９が上面基板２側の流路面に設けられた場合も、微小物体の泳動軌跡が測定電極８の表面近傍を通過し、深さ方向でのばらつきが抑制され、微小物体の測定精度を向上することができることは言うまでもない。 In addition, although the measurement electrode 8 and the migration electrode 9 have been described in the minute object amount measuring apparatus 1 provided on the flow path surface on the bottom substrate 3 side, the measurement electrode 8 and the migration electrode 9 are provided on the flow path surface on the top substrate 2 side. In this case, it is needless to say that the migration trajectory of the minute object passes near the surface of the measurement electrode 8 and variation in the depth direction is suppressed, so that the measurement accuracy of the minute object can be improved.
図４は、実施例２に係る微小物体量検出装置１の上方断面図である。実施例２に係る微小物体量検出装置１は、実施例１の泳動電極９の代わりに磁気回路１９が設けられている。その他の構成に関しては、実施例１と同様なので詳細な説明は省略する。 FIG. 4 is an upper cross-sectional view of the minute object amount detection apparatus 1 according to the second embodiment. In the minute object amount detection apparatus 1 according to the second embodiment, a magnetic circuit 19 is provided instead of the migration electrode 9 according to the first embodiment. Since other configurations are the same as those in the first embodiment, detailed description thereof is omitted.
実施例２では、検体液のインピーダンスを測定するための電極１８と、微小物体を測定電極８の近傍に移動させるための磁気回路１９と、メモリ２０が設けられている。 In the second embodiment, an electrode 18 for measuring the impedance of the sample liquid, a magnetic circuit 19 for moving a minute object to the vicinity of the measurement electrode 8, and a memory 20 are provided.
電極１８は、一対の対向する平板電極が流路５の両側部に配置され、電圧源１５と電流計１６に接続されている。電極１８に直流電圧が印加され、検体液に流れる電流値からインピーダンスを測定できるようになっている。 The electrode 18 has a pair of opposed flat plate electrodes arranged on both sides of the flow path 5 and connected to the voltage source 15 and the ammeter 16. A direct current voltage is applied to the electrode 18 so that the impedance can be measured from the value of the current flowing in the sample liquid.
磁気回路１９は、流路５と交差し底面基板３の流路面と平行方向に磁場を発生させるものであり、磁界の強度を調整できることが好ましい。例えば、図４に示すように、磁気回路１９ａ、１９ｂ間をギャップとするコの字状の鉄心にコイルが巻かれた電磁石を用いることができる。そして、磁気回路１９ａ、１９ｂ間にフローセル４が挟まれるよう配置される。 The magnetic circuit 19 generates a magnetic field in a direction that intersects the flow path 5 and parallel to the flow path surface of the bottom substrate 3, and is preferably capable of adjusting the strength of the magnetic field. For example, as shown in FIG. 4, an electromagnet in which a coil is wound around a U-shaped iron core having a gap between the magnetic circuits 19a and 19b can be used. And it arrange | positions so that the flow cell 4 may be pinched | interposed between the magnetic circuits 19a and 19b.
メモリ２０は、微小物体が備えるプラスまたはマイナスの表面電位（以降、ゼータ電位という）の値を検体液中のインピーダンスと関連付けしたデータとして格納している。 The memory 20 stores a value of a positive or negative surface potential (hereinafter referred to as a zeta potential) included in a micro object as data associated with an impedance in the sample liquid.
磁気回路１９は、上記のように構成され、微小物体のゼータ電位に応じて、磁気回路１９ａ、１９ｂ間の磁場の方向や強度を変えて、微小物体を底面基板３の流路面に引き寄せるローレンツ力を生じさせるようになっている。
（実施例２の処理フロー）
最初に、実施例１と同様に、流路５に流れる検体液のインピーダンスが調整される。ここでは、電極１８で検体液のインピーダンスが測定され、測定電極８の測定範囲を超える場合は、制御手段１７によってバルブ１０が開閉されて検体液に一定量の電解液が加えられる。検体液のインピーダンスが調整された後、メモリ２０に格納されたデータを参照して、検体液のインピーダンスに対応する微小物体のゼータ電位が求められる。
The magnetic circuit 19 is configured as described above, and changes the direction and intensity of the magnetic field between the magnetic circuits 19a and 19b in accordance with the zeta potential of the minute object, thereby drawing the Lorentz force that attracts the minute object to the flow path surface of the bottom substrate 3. It is supposed to give rise to.
(Processing flow of Example 2)
First, as in the first embodiment, the impedance of the sample liquid flowing in the flow path 5 is adjusted. Here, when the impedance of the sample solution is measured by the electrode 18 and exceeds the measurement range of the measurement electrode 8, the valve 10 is opened and closed by the control means 17, and a certain amount of electrolyte is added to the sample solution. After the impedance of the sample liquid is adjusted, the zeta potential of the minute object corresponding to the impedance of the sample liquid is obtained with reference to the data stored in the memory 20.
次に、磁気回路１９ａ、１９ｂ間において、微小物体がプラスのゼータ電位を有する場合は、磁気回路１９ａから１９ｂの方向の磁場が印加され、微小物体がマイナスのゼータ電位を有する場合は、磁気回路１９ｂから１９ａの方向の磁場が印加される。 Next, when the minute object has a positive zeta potential between the magnetic circuits 19a and 19b, a magnetic field in the direction of the magnetic circuit 19a to 19b is applied, and when the minute object has a negative zeta potential, the magnetic circuit A magnetic field in the direction from 19b to 19a is applied.
検体液中に含まれる微小物体は、上記のゼータ電位の極性と磁場の方向との関係により、フローセル４の深さ方向において底面基板３側の流路面に向かうローレンツ力を受ける。また、微小物体に働くローレンツ力は、検体液の流れの力とつりあうように磁場の強度で調整される。具体的には、微小物体が磁場中に滞留されるには至らず、検体液の流れに乗って下流に輸送される程度のローレンツ力である。このため、検体液に含まれる微小物体は、磁気泳動により底面基板３の流路面に引き寄せられながら、同じ底面基板３の流路面に設けられた次段の測定電極８の表面近傍に流れていく。 The micro object contained in the sample liquid receives a Lorentz force toward the flow path surface on the bottom substrate 3 side in the depth direction of the flow cell 4 due to the relationship between the polarity of the zeta potential and the direction of the magnetic field. Further, the Lorentz force acting on the minute object is adjusted by the strength of the magnetic field so as to balance with the force of the sample liquid flow. Specifically, the Lorentz force is such that the minute object does not stay in the magnetic field and is transported downstream along the flow of the sample liquid. For this reason, the minute object contained in the sample liquid flows near the surface of the next-stage measurement electrode 8 provided on the flow path surface of the same bottom substrate 3 while being attracted to the flow path surface of the bottom substrate 3 by magnetophoresis. .
測定電極８間には定電流源１２から検体液のインピーダンスに応じた定電流が印加されており、インピーダンス値と定電流値との積による電圧が電圧計１３に検出される。ここで、検体液中に微小物体が含まれていると、検体液のインピーダンスが変化するため、パルス電圧として検出される。 A constant current according to the impedance of the sample liquid is applied from the constant current source 12 between the measurement electrodes 8, and a voltage resulting from the product of the impedance value and the constant current value is detected by the voltmeter 13. Here, when a minute object is contained in the sample liquid, the impedance of the sample liquid changes, so that it is detected as a pulse voltage.
信号演算手段１４は、電圧計１３で検出されたパルス電圧と閾値を比較し、閾値を超えるパルス電圧の数をカウントする。パルス電圧のカウントは、設定された測定時間内に亘り行われ、測定後、信号演算手段１４で、検体液の流量とパルス電圧のカウント数から微小物体の濃度（個／ｍｌ）が算出される。 The signal calculation means 14 compares the pulse voltage detected by the voltmeter 13 with a threshold value, and counts the number of pulse voltages exceeding the threshold value. The pulse voltage is counted over the set measurement time, and after the measurement, the signal calculation means 14 calculates the concentration (number / ml) of the minute object from the flow rate of the sample liquid and the count number of the pulse voltage. .
以上、説明したように、本発明の微小物体量測定装置１によれば、センサ部の上流側に、微小物体をローレンツ力によってセンサ部の近傍に泳動させる微小物体泳動手段を備えており、微小物体の泳動軌跡がセンサ部の測定電極８の表面近傍を通過するように制御され、微小物体が測定電極８上を通過するときに、深さ方向でのばらつきが抑制されるため、微小物体の測定精度を向上することができる。 As described above, according to the minute object amount measuring apparatus 1 of the present invention, the minute object moving means for moving the minute object to the vicinity of the sensor portion by Lorentz force is provided on the upstream side of the sensor portion. Since the migration trajectory of the object is controlled so as to pass near the surface of the measurement electrode 8 of the sensor unit, and the minute object passes over the measurement electrode 8, variation in the depth direction is suppressed. Measurement accuracy can be improved.
図５は実施例３に係る微小物体量検出装置１の側方断面図である。実施例３に係る微小物体量検出装置１は、実施例２の構成において、微小物体泳動手段として磁気回路１９の代わりに、上面基板２と底面基板３にそれぞれ対向して配置される対向泳動用電極２１ａ、２１ｂを設けている。その他の部分の構成、機能に関しては、実施例２と同様なので説明を省略する。 FIG. 5 is a side sectional view of the minute object amount detection device 1 according to the third embodiment. In the configuration of the second embodiment, the minute object amount detection apparatus 1 according to the third embodiment is used for counter migration, which is disposed as opposed to the top substrate 2 and the bottom substrate 3 instead of the magnetic circuit 19 as a micro object migration unit. Electrodes 21a and 21b are provided. The configuration and functions of other parts are the same as those in the second embodiment, and the description thereof will be omitted.
一方の対向泳動用電極２１ａは底面基板３側の流路面に設けられ、測定電極８の上流側に配置される。対向泳動用電極２１ａは、測定電極８と同材質で真空蒸着やスパッタなどの方法により一緒に形成することができる。他方の対向泳動用電極２１ｂは、上面基板２側の流路面に対向泳動用電極２１ａと対向するように設けられる。対向泳動用電極２１ｂは、対向泳動用電極２１ａと同様の工程で形成できるが、工程を簡略化するため、銀ペーストの塗布等によって設けてもよい。
（実施例３の処理フロー）
実施例２と同様に、実施例３においても、制御手段１７により検体液のインピーダンスを算出した後、メモリ２０に格納されたデータを参照して、検体液のインピーダンスから微小物体のゼータ電位が換算される。
One counter migration electrode 21 a is provided on the flow path surface on the bottom substrate 3 side, and is disposed on the upstream side of the measurement electrode 8. The counter migration electrode 21a can be formed of the same material as the measurement electrode 8 together by a method such as vacuum deposition or sputtering. The other counter migration electrode 21b is provided on the flow path surface on the upper substrate 2 side so as to face the counter migration electrode 21a. The counter migration electrode 21b can be formed in the same process as the counter migration electrode 21a, but may be provided by applying a silver paste or the like to simplify the process.
(Processing flow of Example 3)
Similar to the second embodiment, also in the third embodiment, after the impedance of the sample liquid is calculated by the control means 17, the zeta potential of the minute object is converted from the impedance of the sample liquid by referring to the data stored in the memory 20. Is done.
次に、対向泳動用電極２１ａ、２１ｂ間において、微小物体が正のゼータ電位を有する場合は、対向泳動用電極２１ａから２１ｂの方向の電場を印加し、微小物体が負のゼータ電位を有する場合は、対向泳動用電極２１ｂから２１ａの方向の電場を印加する。 Next, when the minute object has a positive zeta potential between the counter migration electrodes 21a and 21b, an electric field in the direction of the counter migration electrode 21a to 21b is applied, and the minute object has a negative zeta potential. Applies an electric field in the direction of the counter electrophoresis electrodes 21b to 21a.
検体液中の微小物体は、ゼータ電位の極性と、対向泳動用電極２１ａ、２１ｂ間の電場の方向との関係により、フローセル４の深さ方向において底面基板３の流路面に引き寄せられる電気泳動力を受ける。また、微小物体に働く電気泳動力は、検体液の流れの力とつりあうように電場の強度が調整される。具体的には、微小物体が対向泳動用電極２１a、２１ｂ間に拘束されるには至らず、検体液の流れに乗って下流に輸送される程度の電気泳動力である。したがって、検体液に含まれる微小物体は、電気泳動力により底面基板３側の流路面を沿うようにして輸送される。 The microscopic object in the sample liquid is attracted to the flow path surface of the bottom substrate 3 in the depth direction of the flow cell 4 by the relationship between the polarity of the zeta potential and the direction of the electric field between the counter electrophoresis electrodes 21a and 21b. Receive. Further, the electric field strength is adjusted so that the electrophoretic force acting on the minute object is balanced with the flow force of the sample liquid. Specifically, the electrophoretic force is such that the minute object is not restrained between the counter-electrophoresis electrodes 21a and 21b and is transported downstream along the flow of the sample liquid. Therefore, the minute object contained in the sample liquid is transported along the flow path surface on the bottom substrate 3 side by the electrophoretic force.
測定電極８間には定電流源１２から検体液のインピーダンスに応じた定電流が印加されており、インピーダンス値と定電流値との積による電圧が電圧計１３に検出される。ここで、検体液中に微小物体が含まれていると、検体液のインピーダンスが変化し、パルス電圧となって検出される。 A constant current according to the impedance of the sample liquid is applied from the constant current source 12 between the measurement electrodes 8, and a voltage resulting from the product of the impedance value and the constant current value is detected by the voltmeter 13. Here, when a minute object is contained in the sample liquid, the impedance of the sample liquid changes and is detected as a pulse voltage.
信号演算手段１４は、電圧計１３で検出されたパルス電圧と閾値を比較し、閾値を超えるパルス電圧の数をカウントする。パルス電圧のカウントは、設定された測定時間内に亘り行われ、測定後、信号演算手段１４で、検体液の流量とパルス電圧のカウント数から微小物体の濃度（個／ｍｌ）が算出される。 The signal calculation means 14 compares the pulse voltage detected by the voltmeter 13 with a threshold value, and counts the number of pulse voltages exceeding the threshold value. The pulse voltage is counted over the set measurement time, and after the measurement, the signal calculation means 14 calculates the concentration (number / ml) of the minute object from the flow rate of the sample liquid and the count number of the pulse voltage. .
以上、説明したように、本発明の微小物体量測定装置１によれば、センサ部の上流側に、微小物体を電気泳動力によってセンサ部の近傍に泳動させる微小物体泳動手段を備えており、微小物体の泳動軌跡がセンサ部の測定電極８の表面近傍を通過するように制御され、微小物体が測定電極８上を通過するときに、深さ方向でのばらつきが抑制されるため、微小物体の測定精度を向上することができる。 As described above, according to the minute object amount measuring apparatus 1 of the present invention, the minute object migration means for migrating the minute object to the vicinity of the sensor unit by the electrophoretic force is provided on the upstream side of the sensor unit. Since the migration trajectory of the minute object is controlled so as to pass near the surface of the measurement electrode 8 of the sensor unit, and when the minute object passes over the measurement electrode 8, variation in the depth direction is suppressed. The measurement accuracy can be improved.
図６は、実施例４に係る微小物体量検出装置１の上方断面図である。実施例４に係る微小物体量検出装置１は、実施例１に示した微小物体量検出装置１において測定電極８間の流路５の幅を狭める狭窄部７が設けられている。その他の部分の構成、機能に関しては、実施例１と同様なので詳細な説明は省略する。 FIG. 6 is an upper cross-sectional view of the minute object amount detection device 1 according to the fourth embodiment. The minute object amount detection apparatus 1 according to the fourth embodiment is provided with a narrowed portion 7 that narrows the width of the flow path 5 between the measurement electrodes 8 in the minute object amount detection apparatus 1 shown in the first embodiment. Since the configuration and functions of other parts are the same as those in the first embodiment, detailed description thereof is omitted.
狭窄部７は流路５の一部として、上面基板２に流路５や調整路６と一緒に形成される。狭窄部７の間隔は微小物体の大きさに応じて設定されるが、約３０〜１００μｍ程度であることが好ましい。 The narrowed portion 7 is formed as a part of the flow path 5 on the upper substrate 2 together with the flow path 5 and the adjustment path 6. The interval between the narrowed portions 7 is set according to the size of the minute object, but is preferably about 30 to 100 μm.
測定電極８間に狭窄部７を設けることにより、狭窄部７を通過する検体液中の微小物体の密度が高まり、パルス電圧が大きくなるので、測定感度および測定精度をさらに向上させることができる。 By providing the constriction 7 between the measurement electrodes 8, the density of minute objects in the sample liquid passing through the constriction 7 is increased and the pulse voltage is increased, so that the measurement sensitivity and measurement accuracy can be further improved.
なお、狭窄部７は他の実施例２〜３と組合わせて用いることも可能であり、各実施例において測定感度および測定精度をさらに向上させることができる。 In addition, the constriction part 7 can also be used in combination with other Examples 2 and 3, and the measurement sensitivity and the measurement accuracy can be further improved in each Example.
本発明は微小物体量測定装置及び微小物体量測定方法に係るものであり、水中の微生物の数量等の、微小物体の数量を検出する水質センサや上記水質センサを搭載した分析装置、浄水器、洗浄機、浄水プラントなどに利用することができる。 The present invention relates to a minute object amount measuring device and a minute object amount measuring method, and includes a water quality sensor for detecting the number of minute objects, such as the number of microbes in water, an analysis device equipped with the water quality sensor, a water purifier, It can be used for washing machines and water purification plants.
１ 微小物体量検出装置
２ 上面基板
３ 底面基板
４ フローセル
５ 流路
６ 調整路
７ 狭窄部
８ 測定電極
９ 泳動電極
１０ バルブ
１１ 電解液タンク
１２ 定電流源
１３ 電圧計
１２ 磁気回路
１４ 信号演算手段
１５ 電圧源
１６ 電流計
１７ 制御手段
１８ 電極
１９ 磁気回路
２０ メモリ
２１ 対向泳動用電極
DESCRIPTION OF SYMBOLS 1 Minute object amount detection apparatus 2 Top surface board 3 Bottom surface board 4 Flow cell 5 Flow path 6 Adjustment path 7 Narrow part 8 Measurement electrode 9 Electrophoresis electrode 10 Valve 11 Electrolyte tank 12 Constant current source 13 Voltmeter 12 Magnetic circuit 14 Signal calculation means 15 Voltage source 16 Ammeter 17 Control means 18 Electrode 19 Magnetic circuit 20 Memory 21 Electrophoresis electrode
Claims (10)
前記センサ部の上流側に、微小物体を前記センサ部の近傍に泳動させる微小物体泳動手段を備えることを特徴とする微小物体量測定装置。 A micro object amount measuring device for flowing a liquid containing a micro object into a flow cell and measuring the amount of the micro object with a sensor unit provided in the flow cell,
A minute object amount measuring apparatus comprising minute object migration means for migrating a minute object in the vicinity of the sensor unit on the upstream side of the sensor unit.
前記センサ部は、前記流路の一面に形成された一対の平板電極からなり、
前記一対の平板電極は、前記微小物体を含む液体の流れる方向に並設されていることを特徴とする請求項1に記載の微小物体量測定装置。 The flow cell includes a flow path formed by a top substrate and a bottom substrate,
The sensor unit is composed of a pair of flat plate electrodes formed on one surface of the flow path,
2. The minute object amount measuring apparatus according to claim 1, wherein the pair of flat plate electrodes are arranged in parallel in a flowing direction of the liquid containing the minute object.
前記一対の櫛歯電極は、前記センサ部が設けられた流路面に設けられていることを特徴とする請求項３に記載の微小物体量測定装置。 The dielectrophoretic means comprises a pair of comb electrodes,
4. The minute object amount measuring apparatus according to claim 3, wherein the pair of comb electrodes are provided on a flow path surface on which the sensor unit is provided.
前記電磁石は、前記流路と交差し前記センサ部が設けられた流路面と平行方向に磁場を発生することを特徴とする請求項５に記載の微小物体量測定装置。 The means for magnetophoresis comprises an electromagnet,
6. The minute object amount measuring apparatus according to claim 5, wherein the electromagnet generates a magnetic field in a direction parallel to a flow path surface on which the sensor unit is provided and intersects the flow path.
前記一対の平板電極は、前記センサ部が設けられた流路面と、前記センサ部が設けられた流路面と対向する流路面とに設けられていることを特徴とする請求項７に記載の微小物体量測定装置。 The electrophoretic means comprises a pair of plate electrodes,
8. The minute plate according to claim 7, wherein the pair of flat plate electrodes are provided on a flow channel surface provided with the sensor unit and a flow channel surface opposed to the flow channel surface provided with the sensor unit. Object quantity measuring device.
フローセルに流れる検体液のインピーダンスを調整するステップと、
前記インピーダンスに対応して、微小物体の検出に用いる閾値を決定するステップと、
検体液中の微小物体を前記センサ部の近傍に泳動させるステップと、
前記センサ部を通過する検体液に定電流を流し、検体液のインピーダンス変化をパルス電圧として検出するステップと、
前記パルス電圧と前記閾値を比較して微小物体量を求めるステップと、
を含むことを特徴とする微小物体量測定方法。 A method for measuring the amount of a minute object in which a specimen liquid containing a minute object is caused to flow through a flow cell and the minute object is detected by a sensor unit provided in the flow cell,
Adjusting the impedance of the sample liquid flowing in the flow cell;
Determining a threshold to be used for detection of the minute object corresponding to the impedance;
Migrating a minute object in the sample liquid to the vicinity of the sensor unit;
Flowing a constant current through the sample liquid passing through the sensor unit, and detecting a change in impedance of the sample liquid as a pulse voltage;
Comparing the pulse voltage with the threshold value to obtain a minute object amount;
A method for measuring the amount of a minute object, comprising:
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| KR20160027175A (en) * | 2013-07-04 | 2016-03-09 | 사이토모스 리미티드 | Biological sensing apparatus |
| WO2024024238A1 (en) * | 2022-07-29 | 2024-02-01 | 株式会社Ｓｃｒｅｅｎホールディングス | Channel chip, dielectrophoretic device, and control voltage correction method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| KR20160027175A (en) * | 2013-07-04 | 2016-03-09 | 사이토모스 리미티드 | Biological sensing apparatus |
| JP2020003499A (en) * | 2013-07-04 | 2020-01-09 | サイトモス リミテッドＣｙｔｏｍｏｓ Ｌｉｍｉｔｅｄ | Biological sensing apparatus |
| US10933418B2 (en) | 2013-07-04 | 2021-03-02 | Cytomos Limited | Biological analysis apparatus |
| KR102237656B1 (en) * | 2013-07-04 | 2021-04-07 | 사이토모스 리미티드 | Biological sensing apparatus |
| KR20210057068A (en) * | 2013-07-04 | 2021-05-20 | 사이토모스 리미티드 | Biological sensing apparatus |
| KR102418698B1 (en) * | 2013-07-04 | 2022-07-07 | 사이토모스 리미티드 | Biological sensing apparatus |
| WO2024024238A1 (en) * | 2022-07-29 | 2024-02-01 | 株式会社Ｓｃｒｅｅｎホールディングス | Channel chip, dielectrophoretic device, and control voltage correction method |
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