JPS6117948A - Immobilized enzyme film for enzyme electrode - Google Patents
Immobilized enzyme film for enzyme electrodeInfo
- Publication number
- JPS6117948A JPS6117948A JP59139318A JP13931884A JPS6117948A JP S6117948 A JPS6117948 A JP S6117948A JP 59139318 A JP59139318 A JP 59139318A JP 13931884 A JP13931884 A JP 13931884A JP S6117948 A JPS6117948 A JP S6117948A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- immobilized enzyme
- enzyme
- membrane
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/001—Enzyme electrodes
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Zoology (AREA)
- Wood Science & Technology (AREA)
- Proteomics, Peptides & Aminoacids (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Microbiology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Biotechnology (AREA)
- Biophysics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Bioinformatics & Cheminformatics (AREA)
- General Engineering & Computer Science (AREA)
- General Health & Medical Sciences (AREA)
- Genetics & Genomics (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の属する技術分野〕
この発明は酵素電極用の固定化酵素膜に係り、詳細には
酵素反応に必要な酸素を供給し、溶゛存酸素量の少ない
試料液であつそも、その試料液の一基質濃度に対応した
反応を起こし得る膜構造を備えた固定化酵素膜に簡する
１゜
〔従来技術とその問題点〕
近年、酵素電極を用いて多成分溶液中の特定物質を分析
する技術が開発されている。これは一般に、検体を緩衝
液にて希釈し、緩衝液中の溶存酸素と水と基質を酵素で
選択的に一伎応させて酸素量の減少、もしくは過酸化水
素等の反応生成物−を電極にて測定し、それにより検体
中の特定物質を定量的に測定するものである。[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] This invention relates to an immobilized enzyme membrane for enzyme electrodes, and more specifically, to an immobilized enzyme membrane for enzyme electrodes, which supplies oxygen necessary for enzyme reactions, and which is suitable for use in sample liquids with a low amount of dissolved oxygen. In recent years, enzyme electrodes have been used to produce an immobilized enzyme membrane with a membrane structure capable of causing a reaction corresponding to the concentration of one substrate in the sample solution. Techniques have been developed to analyze specific substances in solutions. Generally, this is done by diluting the sample with a buffer solution and selectively reacting the dissolved oxygen, water, and substrate in the buffer solution with an enzyme to reduce the amount of oxygen or generate reaction products such as hydrogen peroxide. This method uses electrodes to quantitatively measure specific substances in a sample.
しかし、この方法は検体を正確な希釈率で希釈する操作
もしくは装置を必要とした。However, this method required an operation or device to dilute the sample at a precise dilution rate.
また、前述の希釈操作を省き、非希釈検体を直接的にか
つ簡易に測定し得るグルコース分析法も開発されている
。この方法は検体中の水と酸素によシ酵素反応を生ぜし
め、反応生成物である過酸化水素を電極にて測定するも
のであるが、検体中の溶存酸素を必要とするだめ、静脈
血液等、溶存酸素の少ない検体を測定する場合、出力が
低濃度の酸素量により支配され、出力の飽和が観測され
て不完全であった。Furthermore, a glucose analysis method has also been developed that eliminates the dilution operation described above and allows direct and simple measurement of undiluted specimens. This method involves an enzymatic reaction between water and oxygen in the sample, and the reaction product, hydrogen peroxide, is measured using an electrode. However, since dissolved oxygen in the sample is required, venous blood When measuring samples with low dissolved oxygen, such as samples, the output was dominated by the low concentration of oxygen, and saturation of the output was observed, resulting in incomplete measurements.
この発明の目的は酵素反応に必要な酸素を供給し、溶存
酸素の少ない試料液であってもこの影響を受けることな
く試料液の基質濃度に対応した反応を起こし得る、前述
の従来技術に存する欠点を解消した酵素電極用の固定化
酵素膜を提供することにある。。The purpose of the present invention is to supply the oxygen necessary for an enzyme reaction, and to overcome the above-mentioned conventional technology, it is possible to cause a reaction corresponding to the substrate concentration of the sample solution without being affected by this effect even in a sample solution with little dissolved oxygen. An object of the present invention is to provide an immobilized enzyme membrane for an enzyme electrode that eliminates the drawbacks. .
上述の目的を達成するため、本発明によれば、固定化酵
素層を有する酵素電極用固定化酵素膜であって、前記固
定化酵素層の被測定試料側の表面に含水層を設けたこと
を特薮とする。In order to achieve the above object, the present invention provides an immobilized enzyme membrane for an enzyme electrode having an immobilized enzyme layer, in which a water-containing layer is provided on the surface of the immobilized enzyme layer on the side of the sample to be measured. is a special bush.
以下、本発明固定化酵素膜を添付図面を用いて詳述する
。The immobilized enzyme membrane of the present invention will be described in detail below with reference to the accompanying drawings.
第１図は本発明にかかる固定化酵素膜の一具体例の膜構
造を表わした断面図であって、１は保護膜、２は含水層
、３は固定化酵素層、４は選択透過膜、５はクラーク型
電極である。第１図の膜構造は保護膜１上に含水層２を
形成し、その上に固定化酵素層３、さらにその上に選択
透過膜４を形成することによって構成され、これをクラ
ーク型電極５に装着することにより酵素電極が構成され
る。このような本発明において、含水層２は固定化酵素
層３の被測定試料側の表面に形成されることになシ、こ
れにより酵素反応に必要な酸素が含・ 水層２中の水溶
液成分中の溶存酸素として供給される。FIG. 1 is a cross-sectional view showing the membrane structure of a specific example of the immobilized enzyme membrane according to the present invention, in which 1 is a protective film, 2 is a water-containing layer, 3 is an immobilized enzyme layer, and 4 is a selectively permeable membrane. , 5 are Clark type electrodes. The membrane structure shown in FIG. 1 is constructed by forming a water-containing layer 2 on a protective membrane 1, an immobilized enzyme layer 3 on top of it, and a selectively permeable membrane 4 on top of it. An enzyme electrode is constructed by attaching the electrode to the electrode. In the present invention, the water-containing layer 2 is formed on the surface of the immobilized enzyme layer 3 on the side of the sample to be measured. It is supplied as dissolved oxygen in the water.
この発明において、含水層としてはポリビニルアルコー
ル、牛血清アルブミンなどの含水性の高分子層が用いら
れるが、もちろん、これらに限られるものではない。壕
だ、前記含水層中にカタラーゼを固定化し、酸素の供給
効率を向−卜せしめることもできる。In this invention, a water-containing polymer layer such as polyvinyl alcohol or bovine serum albumin is used as the water-containing layer, but is not limited to these. Alternatively, catalase can be immobilized in the water-containing layer to improve oxygen supply efficiency.
以下、本発明を実施例によりさらに詳述する。Hereinafter, the present invention will be explained in more detail with reference to Examples.
実施例−１
第１図における膜構造を以下のようにして製造した。ま
ず、保護膜１としてポリカーボネート多孔膜１（孔径０
０１５μｍ）を用意し、この上に蒸留水に溶かした１０
重量％水溶性ポリビニルアルコールを塗布し、これをさ
らに１０重量％グルタルアルデヒド、１０重量％硫酸ナ
トリウムおよびＩＮ塩酸の混合液（混合比１：１：１）
中に浸漬して４００Ｃの温度で３時間反応させ、厚さ３
乃至６μｍの不飽和ポリビニルアルコール層からなる含
水層２を形成した。Example 1 The membrane structure shown in FIG. 1 was manufactured as follows. First, as the protective film 1, a polycarbonate porous film 1 (pore size 0
Prepare 015 μm) and add 10 μm dissolved in distilled water on top of this.
% by weight water-soluble polyvinyl alcohol is applied, and this is further coated with a mixture of 10% by weight glutaraldehyde, 10% by weight sodium sulfate, and IN hydrochloric acid (mixing ratio 1:1:1).
immersed in the liquid and reacted at a temperature of 400C for 3 hours to form a film with a thickness of 3
A water-containing layer 2 consisting of an unsaturated polyvinyl alcohol layer with a thickness of 6 μm to 6 μm was formed.
次いで、０１Ｍリン酸緩衝液（ＰＨ６，０）を用いて牛
血清アルブミン溶液（４０ｍｇ／ｄりを調製し、さらに
この溶液を用いてグルコースオキシダーゼが１０ｍｊ／
ｄＪ−に々るように調整１／、さらにグルタルアルデヒ
ドを２重量％となるように添加して酵素溶液を訓製し、
前記含水層２を蒸留水でよく洗浄の移、この酵素溶液１
０μ）を含水層２（不飽和ポリビニルアルコール層２）
の上に展開して固定化酵素層３を形成した。Next, a bovine serum albumin solution (40 mg/d) was prepared using 01M phosphate buffer (PH6.0), and this solution was used to increase glucose oxidase to 10 mj/d.
dJ-adjusted to 1/2 and further added glutaraldehyde to 2% by weight to prepare an enzyme solution,
The water-containing layer 2 was thoroughly washed with distilled water, and the enzyme solution 1
0μ) as water-containing layer 2 (unsaturated polyvinyl alcohol layer 2)
The immobilized enzyme layer 3 was formed by developing the immobilized enzyme layer 3 on top of the .
さらに前記固定化酵素層３上資膜厚６乃至７μｍの酢酸
セルロース世帯ｉからなる癲択透過膜４を重ねて４°’
Ｃ，２００時間反応せ、゛その後、０．０５ Ｍ ｉｔ
ン酸緩衝液（ＰＨ７，０）で洗浄し、４°Ｃの膜）を、
次いでクラーク型電極ｉに装着して酵素電極を構成した
。Furthermore, a selectively permeable membrane 4 made of cellulose acetate having a membrane thickness of 6 to 7 μm is superimposed on the immobilized enzyme layer 3 to form a 4°'
C, react for 200 hours, then 0.05 M it
Wash the membrane with acid buffer (pH 7,0) and store at 4 °C.
Next, it was attached to a Clark type electrode i to form an enzyme electrode.
このような酵素電極において、いま、グルコースの溶存
している゛検体（被測定試料）が固定化酵素膜Ａの保護
膜１（ポリカーボネート多孔膜１）に触れると、検体は
ポリカーボネート多孔膜ｌと透過膜４（酢酸セルロース
膜４）を透過してクラーク型電極５（過酸化水素電極）
で検知される１゜この場合、検体中に溶存酸素が少ない
と、従来の不溶化ポリビニル層２のない固定化酵素膜で
は酸素不足を起こして反応で生成する過酸化水素量の低
下が生じ、酵素電極の出力が飽和してくる。しかし、こ
の発明による固定化酵素膜Δでは、不溶化ポリビニルア
ルコールからなる含水層２を有するため、含水層２よす
溶存酸素が供給され、とのため反応は継続されて本来の
出力が得られる１゜第２図１３、出力の経時変化を表わ
したグラフであって、（４）はグルコース溶液を従来の
固定化酵素膜を用いた酵素電極で計測したときの出力フ
オームを示し、Ｑ３）は前記（４）に対して溶存酸素量
が３０％のグルコース溶液を試料としたときの前記■と
同じ酵素電極による出力フオームを示し、ｎは前記（Ｂ
）と同様な試料を用いて、本発明による固定化酵素膜を
用いた酵素電極で計測したときの出力フオームを示す。In such an enzyme electrode, when a specimen (sample to be measured) containing dissolved glucose touches the protective film 1 (polycarbonate porous membrane 1) of the immobilized enzyme membrane A, the specimen passes through the polycarbonate porous membrane 1. It passes through the membrane 4 (cellulose acetate membrane 4) and passes through the Clark type electrode 5 (hydrogen peroxide electrode).
In this case, if there is little dissolved oxygen in the sample, the conventional immobilized enzyme membrane without the insolubilized polyvinyl layer 2 will lack oxygen, resulting in a decrease in the amount of hydrogen peroxide produced in the reaction, and the enzyme The output of the electrode becomes saturated. However, since the immobilized enzyme membrane Δ according to the present invention has a water-containing layer 2 made of insolubilized polyvinyl alcohol, dissolved oxygen is supplied to the water-containing layer 2, so that the reaction continues and the original output can be obtained.゜ Fig. 2 13 is a graph showing the change in output over time, where (4) shows the output form when a glucose solution is measured with an enzyme electrode using a conventional immobilized enzyme membrane, and Q3) shows the output form as described above. For (4), the output form from the same enzyme electrode as in (■) above is shown when a glucose solution with a dissolved oxygen content of 30% is used as a sample, and n is the output form (B
) shows the output form when measured with an enzyme electrode using an immobilized enzyme membrane according to the present invention using a sample similar to that shown in FIG.
なお、６は計測ポイントである。Note that 6 is a measurement point.
第２図（ト）、（Ｂ）、（Ｃ）から、本発明による固定
化酵素膜を用いれば、試料中の溶存酸素量の影響を受け
ることなく基質濃度が計測可能であることがわかる。It can be seen from FIGS. 2(G), (B), and (C) that by using the immobilized enzyme membrane according to the present invention, the substrate concentration can be measured without being affected by the amount of dissolved oxygen in the sample.
実施例−２
実施例−１と同様のポリカーボネート多孔膜１上に、０
．５Ｍリン酸緩衝液（ＰＨ６，０）１ｍＪ、牛血清アル
ブミン２５ｒｎ、Ｉｌ、 ２５％グルタルアルデヒド１
００μｍからなる溶液をゲル状で塗布した後、４°Ｃの
温度で３時間乾燥させ、３乃至６μｍの不溶化アルブミ
ン層２（含水層２）を形成した。得られた不溶化アルブ
ミン層２上に実施例１と同様の酵素溶液１０μＬを展開
して固定化酵素層３を形成し、その上に膜厚６乃至７μ
ｍの酢酸セルロース４ｆＬ密膜４を重ねて４°Ｃの温度
で２０時間反応させ、その後、００５Ｍリン酸緩衝液（
ＰＨ７，０）で洗浄し、４°Ｃで乾燥して固定化酵素膜
Δを得た。Example-2 On the same polycarbonate porous membrane 1 as in Example-1, 0
．． 5M phosphate buffer (PH6,0) 1mJ, bovine serum albumin 25rn, Il, 25% glutaraldehyde 1
After applying a solution consisting of 00 μm in gel form, it was dried at a temperature of 4° C. for 3 hours to form an insolubilized albumin layer 2 (water-containing layer 2) with a thickness of 3 to 6 μm. 10 μL of the same enzyme solution as in Example 1 is spread on the obtained insolubilized albumin layer 2 to form an immobilized enzyme layer 3, and a film thickness of 6 to 7 μL is formed on the immobilized enzyme layer 3.
4 fL of cellulose acetate 4 was layered and reacted for 20 hours at a temperature of 4°C, and then added with 005M phosphate buffer (
The membrane was washed with pH 7,0) and dried at 4°C to obtain an immobilized enzyme membrane Δ.
前述の固定化酵素膜Δをクラー型過酸化水素電極５と組
み合わせて酵素電極を構成し、この酵素電極を用いて溶
存酸素量の少ないグルコース溶液を測定しても計測ポイ
ントまで出力が飽和しなかった。An enzyme electrode is constructed by combining the above-mentioned immobilized enzyme membrane Δ with the Clar-type hydrogen peroxide electrode 5, and even when a glucose solution with a small amount of dissolved oxygen is measured using this enzyme electrode, the output does not become saturated up to the measurement point. Ta.
以上のとおシ、本発明にかかる固定化酵素膜は固定化酵
素層の被測定試料側の表面、すなわち、第１図に示され
るように保護膜１と固定化酵素層３の間に含水層２を設
けたから、との含水層から酵素反応に必要な酸素が供給
され、溶存酸素量の少ない試料液でも出力が飽和するこ
となく測定でき、特に全血中の血糖値を計測する場合、
個々人により差のある血液中の溶存酸素量の影響を受け
゛ることがなくなり、実用上極めて有用である。As described above, the immobilized enzyme membrane according to the present invention has a water-containing layer on the surface of the immobilized enzyme layer on the side of the sample to be measured, that is, as shown in FIG. 2, the oxygen necessary for the enzyme reaction is supplied from the water-containing layer, and even sample liquids with a small amount of dissolved oxygen can be measured without saturating the output, especially when measuring blood sugar levels in whole blood.
This is extremely useful in practice since it is not affected by the amount of dissolved oxygen in the blood, which varies from person to person.
第１図は本発明にかかる固定化酵素膜の膜構造を表わし
だ断面図を示し、第２図囚は従来の固定化酵素膜により
得られた出力フオーム、第２図（Ｂ）は従来の固定化酵
素膜を用いて溶存酸素の少ない試料液を測定したときの
出力フオーム、第２図（Ｃ）は本発明にかかる固定化酵
素膜を用いて溶存酸素量の少ない試料液を計測したとき
の出力フオームをそれぞれ示す。
ｌ・・・保護膜（ポリカーボネート多孔膜）、２・・・
含水層、３・・・固定化酵素層、４・・・選択透過膜（
酢酸セルロース（改密膜）
５・・・クラーク型電極、６・・・計測ポイント。FIG. 1 shows a cross-sectional view showing the membrane structure of the immobilized enzyme membrane according to the present invention, FIG. The output form when measuring a sample liquid with a low amount of dissolved oxygen using the immobilized enzyme membrane, Figure 2 (C) shows the output form when measuring a sample liquid with a low amount of dissolved oxygen using the immobilized enzyme membrane according to the present invention. The output forms of are shown respectively. l...protective film (polycarbonate porous film), 2...
water-containing layer, 3... immobilized enzyme layer, 4... selectively permeable membrane (
Cellulose acetate (modified membrane) 5...Clarke type electrode, 6...Measurement point.
Claims (1)
、前記固定化酵素層の被測定試料側の表面に含水層を設
けたことを特徴とする酵素電極用固定化酵素膜。1. An immobilized enzyme membrane for an enzyme electrode having an immobilized enzyme layer, characterized in that a water-containing layer is provided on the surface of the immobilized enzyme layer on the side of the sample to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59139318A JPS6117948A (en) | 1984-07-05 | 1984-07-05 | Immobilized enzyme film for enzyme electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59139318A JPS6117948A (en) | 1984-07-05 | 1984-07-05 | Immobilized enzyme film for enzyme electrode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6117948A true JPS6117948A (en) | 1986-01-25 |
Family
ID=15242513
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59139318A Pending JPS6117948A (en) | 1984-07-05 | 1984-07-05 | Immobilized enzyme film for enzyme electrode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6117948A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6287135A (en) * | 1985-09-18 | 1987-04-21 | チルドレンズ ホスピタル メデイカル センタ− | Implantable gas-containing biosensor and measurement of substance to be analyzed such as glucose |
| JPS63317096A (en) * | 1987-06-19 | 1988-12-26 | Matsushita Electric Ind Co Ltd | Biosensor |
| JP2007003265A (en) * | 2005-06-22 | 2007-01-11 | Techno Medica Co Ltd | Electrode structure and enzyme sensor including it for measuring phosphoric acid in body fluids |
| JP2008501415A (en) * | 2004-06-04 | 2008-01-24 | メドトロニック ミニメド インコーポレイテッド | TEST SENSOR AND MANUFACTURING METHOD AND USING THE SAME |
| CN105223253A (en) * | 2015-09-28 | 2016-01-06 | 深圳市美特瑞科技发展有限公司 | A kind of galvanochemistry ethanol sensor based on alcohol oxidase and preparation method thereof |
-
1984
- 1984-07-05 JP JP59139318A patent/JPS6117948A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6287135A (en) * | 1985-09-18 | 1987-04-21 | チルドレンズ ホスピタル メデイカル センタ− | Implantable gas-containing biosensor and measurement of substance to be analyzed such as glucose |
| JPS63317096A (en) * | 1987-06-19 | 1988-12-26 | Matsushita Electric Ind Co Ltd | Biosensor |
| JP2008501415A (en) * | 2004-06-04 | 2008-01-24 | メドトロニック ミニメド インコーポレイテッド | TEST SENSOR AND MANUFACTURING METHOD AND USING THE SAME |
| JP2007003265A (en) * | 2005-06-22 | 2007-01-11 | Techno Medica Co Ltd | Electrode structure and enzyme sensor including it for measuring phosphoric acid in body fluids |
| JP4690122B2 (en) * | 2005-06-22 | 2011-06-01 | 株式会社テクノメディカ | Electrode structure and enzyme sensor for measuring phosphate in body fluid containing the same |
| CN105223253A (en) * | 2015-09-28 | 2016-01-06 | 深圳市美特瑞科技发展有限公司 | A kind of galvanochemistry ethanol sensor based on alcohol oxidase and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| van der Schoot et al. | ISFET based enzyme sensors | |
| Skládal | Advances in electrochemical immunosensors | |
| Palleschi et al. | Amperometric tetrathiafulvalene-mediated lactate electrode using lactate oxidase absorbed on carbon foil | |
| Coulet | Polymeric membranes and coupled enzymes in the design of biosensors | |
| JP2646848B2 (en) | Glucose sensor measurement method | |
| Shul'ga et al. | Thin-film conductometric biosensors for glucose and urea determination | |
| Wu et al. | Electrochemical immunoassay for CA125 based on cellulose acetate stabilized antigen/colloidal gold nanoparticles membrane | |
| JPS5921500B2 (en) | Enzyme membrane for oxygen electrode | |
| JPH04503249A (en) | Completely microfabricated biosensor, its manufacturing method and its use | |
| JPH01156658A (en) | Biosensor | |
| JPH0363018B2 (en) | ||
| JPH0235933B2 (en) | ||
| Soldatkin et al. | Glucose sensitive conductometric biosensor with additional Nafion membrane: reduction of influence of buffer capacity on the sensor response and extension of its dynamic range | |
| JPH02131500A (en) | Proteopexic method and its device | |
| JPH10267888A (en) | Biosensor | |
| Tamiya et al. | Micro-biosensors for clinical analyses | |
| KR870008189A (en) | Enzyme sensor and manufacturing method | |
| JPS6117948A (en) | Immobilized enzyme film for enzyme electrode | |
| Winartasaputra et al. | Amperometric enzymic determination of triglycerides in serum | |
| JPS60185153A (en) | Immobilized enzyme membrane | |
| JPS61145447A (en) | Immobilized enzyme membrane | |
| JPS6375655A (en) | Enzyme electrode apparatus | |
| JPH043500B2 (en) | ||
| JP2862940B2 (en) | Immobilized enzyme and measuring device using the same | |
| Vadgama | Biosensors: adaptation for practical use |