【発明の詳細な説明】（産業上の利用分野）この発明は、測定対象溶質の定電位電解反応によって生
じるイオン濃度から対象溶＊濃度を求める濃度測定装置
に間するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a concentration measuring device that determines the concentration of a target solute from the ion concentration generated by a constant potential electrolytic reaction of the solute to be measured.
（従来の技術）イオンセンサによる溶媒中の特定溶質の濃度測定には、
従来、次のような装置が用いられている。(Conventional technology) To measure the concentration of a specific solute in a solvent using an ion sensor,
Conventionally, the following devices have been used.
ｌ）溶質が電解質の場合溶質の熱的な電離平衡反応によって生じるイオン濃度の
検出を特徴とする濃度測定装置。l) When the solute is an electrolyte, a concentration measuring device characterized by detecting the ion concentration generated by a thermal ionization equilibrium reaction of the solute.
上記イオン濃度は溶媒に溶けた溶質濃度に比例するから
、イオン濃度を測定すれば、対象溶質の濃度がわかるの
を測定原理としている。Since the ion concentration is proportional to the solute concentration dissolved in the solvent, the measurement principle is that by measuring the ion concentration, the concentration of the target solute can be determined.
２）溶質が非電解質の場合非電解質から電解質を生成する物、例えば、酵素や微生
物等がイオン感応部またはその近傍に固定されたイオン
検出部もつ濃度測定装置非電解質から電解質を生成する物、例えば、酵素や微生
物等をイオン感応部またはその近傍に固定されていると
、非電解質の溶質に比例した電解質が生成され、この生
成された電解質の濃度に比例したイオンが熱的な電離平
衡反応によって生じ、イオン濃度測定から間接的に非電
解質の濃度が測定されている。2) When the solute is a non-electrolyte, a device that generates an electrolyte from a non-electrolyte, such as a concentration measuring device that has an ion-sensing section in which enzymes, microorganisms, etc. are fixed at or near the ion-sensing section; For example, when enzymes, microorganisms, etc. are immobilized on or near the ion-sensing part, an electrolyte is produced in proportion to the non-electrolyte solute, and ions proportional to the concentration of the produced electrolyte undergo a thermal ionization equilibrium reaction. The concentration of non-electrolytes is measured indirectly from the measurement of ion concentration.
（発明が解決しようとする課題）上記の濃度測定装置は、溶質の一部が熱的に電離平衡反
応して生じるイオン濃度を測定の原理にしている。した
がって、溶質濃度の測定下限は溶質の電離度を支配する
電離定数に左右され、電離定数の小さい溶質の濃度の測
定は困難になる。(Problems to be Solved by the Invention) The concentration measuring device described above uses the ion concentration generated by a thermal ionization equilibrium reaction of a part of the solute as the principle of measurement. Therefore, the lower limit of solute concentration measurement depends on the ionization constant that governs the degree of ionization of the solute, making it difficult to measure the concentration of solutes with small ionization constants.
本願の第一の発明は、電離平衡定数の小さい溶質の濃度
測定が困難である上記の欠点を改善することを課題とし
て為したものであり、第二の発明は非電解質の濃度測定
における濃度検出感度の改善を為したものである。The first invention of the present application has been made with the aim of improving the above-mentioned drawback that it is difficult to measure the concentration of solutes with small ionization equilibrium constants, and the second invention is directed to concentration detection in the concentration measurement of non-electrolytes. The sensitivity has been improved.
（課題を解決するための手段）（−）第一の発明の要点は、作用電極（１）とイオン感
応性電界効果型トランジスタ（以降Ｉ ５ＦＥＴと略称
する）（２）のイオン感応部（３）とが近接して構成さ
れることにある。(Means for Solving the Problem) (-) The gist of the first invention is that the working electrode (1) and the ion-sensitive part (3) of the ion-sensitive field effect transistor (hereinafter abbreviated as I5FET) (2) ) are arranged in close proximity.
に）第二の発明の要点は、作用電極（１）または１５Ｆ
ＥＴ（２）のイオン感応部（３）の少なくとも何れかの
表面またはその近傍に、少なくともその何れかに、非電
解質から電解質を生成する物（１１）、例えば、酵素や
微生物等の固定された作用電極（１）と１５ＦＥＴ（２
）のイオン感応部（３）とが近接して構成されることに
ある。) The main point of the second invention is that the working electrode (1) or 15F
A substance (11) that generates an electrolyte from a non-electrolyte, such as an enzyme or a microorganism, is immobilized on or near at least one of the surfaces of the ion-sensing part (3) of the ET (2). Working electrode (1) and 15FET (2
) are arranged in close proximity to the ion-sensing section (3).
（発明の作用）本願の第一の発明は、測定対象溶質の定電位電解によっ
て、測定対象溶質濃度に比例して生じるイオン濃度のＩ
５ＦＥＴによる検出値から対象溶質の濃度が測定され
る。(Function of the Invention) The first invention of the present application is that the ion concentration is generated in proportion to the concentration of the solute to be measured by constant potential electrolysis of the solute to be measured.
The concentration of the target solute is measured from the value detected by the 5FET.
第二の発明は、測定対象の非電解質の溶質から生成され
る電解質の定電位電解によって、測定対象溶質濃度に比
例して、生じるイオン濃度のＩ ５ＦＥＴによる検出値
から対象溶質の濃度が測定される。In the second invention, the concentration of the target solute is measured from the detected value of the ion concentration generated by the I5FET in proportion to the concentration of the target solute by constant potential electrolysis of the electrolyte generated from the non-electrolyte solute to be measured. Ru.
（実施例）（第一発明の実施例）図面の第１図は第一発明の実施例を示す溶質濃度測定装
置の回路である。第２図および第３図は、作用電極（１
）および対向電極（４）と１５ＦＥＴ（２）が絶縁物（
５）で固定された溶質濃度検出部（１４）の図である。(Example) (Example of the first invention) FIG. 1 of the drawings is a circuit of a solute concentration measuring device showing an example of the first invention. Figures 2 and 3 show the working electrode (1
) and the counter electrode (4) and 15FET (2) are insulators (
5) is a diagram of the solute concentration detection unit (14) fixed in FIG.
第４図および第５図は、作用電極（１）が１５ＦＥＴ（
２）のイオン感応部３に近接して作り付けられ、対向電
極（４）が１５ＦＥＴ（２）の装着されている絶縁基板
（６）の裏面に作り付けられて一体化された溶質濃度検
出部（１４）の図である。4 and 5, the working electrode (1) is a 15FET (
The solute concentration detection section (14) is built close to the ion sensing section 3 of 2), and the counter electrode (4) is built and integrated on the back surface of the insulating substrate (6) on which the 15FET (2) is mounted. ).
第１図において、第一発明の実施例の測定回路系にって
説明する。Referring to FIG. 1, a measurement circuit system according to an embodiment of the first invention will be explained.
比較電極（１２）は作用電極（１）と溶媒（１３）との
界面間の電圧を正確に測定するための電極である。The reference electrode (12) is an electrode for accurately measuring the voltage across the interface between the working electrode (1) and the solvent (13).
測定対象溶質の電解に必要な電圧は、作用電極（１）と
対向電極（４）に印加される。設定電圧（］５）で設定
される作用電極（１）と比較電極（１２）との電位差は
、増幅器（１６）によって常に、測定対象の溶質が選択
的に電解される一定の電圧に制御される。The voltage necessary for electrolyzing the solute to be measured is applied to the working electrode (1) and the counter electrode (4). The potential difference between the working electrode (1) and the reference electrode (12), which is set by the set voltage (5), is always controlled by the amplifier (16) to a constant voltage at which the solute to be measured is selectively electrolyzed. Ru.
設定電圧（１７）で設定された１５ＦＥＴ（２）のドレ
ーン（８）・ソース（９）間の電圧は増幅器（１８）に
よって常に一定に制御されている。The voltage between the drain (8) and source (9) of the 15FET (2) set at the set voltage (17) is always controlled to be constant by the amplifier (18).
作用電極（１）に触れた測定対象溶質は電解され、イオ
ンが生じる。このイオンに選択的に感応し濃度に応じて
１５ＦＥＴ（２）のイオン感応部（３）に設けたイオン
選択膜（７）と溶媒（１３）との界面間に電圧が生じる
。この界面電圧とソース（９）の電圧との和の電圧がイ
オン選択膜（７）とソース（９）との間に印加される。The solute to be measured that touches the working electrode (1) is electrolyzed and ions are generated. It is selectively sensitive to these ions, and a voltage is generated between the interface between the ion-selective membrane (7) provided in the ion-sensing part (3) of the 15FET (2) and the solvent (13) depending on the concentration. A voltage equal to the sum of this interfacial voltage and the voltage of the source (9) is applied between the ion selective membrane (7) and the source (9).
この電圧によってチャンネル（１０）に電子が誘引され
、このチャンネル（１０）の抵抗が変化し、ドレーン（
８）からソース（９〉へ流れる電流が変化する。この′
ｒＩＬ流の変化は測定対象の溶質の濃度に対応した出力
電圧（１９）となって出力される。Electrons are attracted to the channel (10) by this voltage, the resistance of this channel (10) changes, and the drain (
The current flowing from 8) to the source (9〉) changes.
Changes in the rIL flow are output as an output voltage (19) corresponding to the concentration of the solute to be measured.
第一発明による過酸化水素の濃度測定結果を第６図に示
す。第６図は水溶液中の過酸化水素の濃度変化に対する
濃度測定装置の出力入電圧変化である。The results of measuring the concentration of hydrogen peroxide according to the first invention are shown in FIG. FIG. 6 shows changes in the output and input voltage of the concentration measuring device with respect to changes in the concentration of hydrogen peroxide in an aqueous solution.
第１図を用いて、過酸化水素の濃度測定実施例の測定回
路系を説明する。The measurement circuit system of an embodiment for measuring the concentration of hydrogen peroxide will be explained with reference to FIG.
第１図において、溶媒（１３）として脱イオン水を使用
し、室内雰囲気との平衡がとれた後に、これに過酸化水
素溶液を滴下して濃度測定装置の出力電圧（１９）の変
化を調べた。In Figure 1, deionized water is used as the solvent (13), and after equilibrium with the room atmosphere is achieved, a hydrogen peroxide solution is dropped into it and the change in the output voltage (19) of the concentration measuring device is examined. Ta.
この溶質濃度検出に使用された溶質濃度検出部（１４）
の構造は第２図および第３図に示す構造である０作用電
極（１）と対向電極（４）に、それぞれ、白金線を使用
し、Ｉ ５ＦＥＴと共にシリコン樹脂で固定された。Solute concentration detection section (14) used for this solute concentration detection
The structure is shown in FIGS. 2 and 3, using platinum wires for the working electrode (1) and counter electrode (4), respectively, and fixed with silicone resin together with the I5FET.
比較電極（１２）として銀塩化銀電極（Ａｇ／ ＡｇＣ
１）を使用した。過酸化水素の電解のために、比較電極
（１２）に対して作用電極（１）が０．７ Ｖになるよ
うに設定電圧（１５）で設定された。A silver-silver chloride electrode (Ag/AgC) was used as a comparison electrode (12).
1) was used. For the electrolysis of hydrogen peroxide, the working electrode (1) was set at a set voltage (15) of 0.7 V with respect to the reference electrode (12).
電解で生じるイオン検出のためのＩ ５ＦＥＴ（２）の
ドレーン（８）・ソース（９）間の電圧は設定電圧（１
７）によって１ｖに設定された。The voltage between the drain (8) and source (9) of the I5FET (2) for detecting ions generated in electrolysis is the set voltage (1
7) was set to 1v.
第６図において、実線は本発明による測定電圧である。In FIG. 6, the solid line is the measured voltage according to the present invention.
破線は、作用電極（１）と対向電極（４）に電圧を印加
しない開放状態、即ち、従来の１５ＦＥＴ（２）のみに
よる濃度測定電圧である。The broken line represents the open state in which no voltage is applied to the working electrode (1) and the counter electrode (4), that is, the concentration measurement voltage using only the conventional 15FET (2).
脱イオン水が過酸化水素の最初の滴下によって１２１１
１１ｂの過酸化水素水溶液に変化したとき、本発明によ
る濃度測定装置の出力電圧（１９）は１０ａ＋Ｖ変化す
る。これに対して、作用電極（１）と対向電極（４）に
電圧を印加しない開放状態（従来の１５ＦＥＴ（２）の
みによる検出状態）では、脱イオン水が１２０００ ｐ
ｐｂの過酸化水素の濃度に達したとき、はじめて、１０
ｍｖの出力電圧変化が得られた。Deionized water is added to 1211 by the first drop of hydrogen peroxide.
When the hydrogen peroxide aqueous solution 11b changes, the output voltage (19) of the concentration measuring device according to the present invention changes by 10a+V. On the other hand, in the open state where no voltage is applied to the working electrode (1) and the counter electrode (4) (detection state using only the conventional 15FET (2)), deionized water is 12000 p
Only when a concentration of hydrogen peroxide of pb is reached, 10
An output voltage change of mv was obtained.
この結果から本発明の濃度測定装置による過酸化水素の
検出は従来のＩ ５ＦＥＴのみによる検出濃度の下限の
１０００分の１まで可能である。即ち、１０００倍の測
定感度が得られた。From this result, it is possible to detect hydrogen peroxide using the concentration measuring device of the present invention down to 1/1000 of the lower limit of the detection concentration using only the conventional I5FET. That is, a measurement sensitivity of 1000 times was obtained.
（第二発明の実施例）第７図、第８図、第９図、第１０図、第１１図、第１２
図は、第二発明の実施例である、非電解質の溶質濃度検
出部（１４）の図である。(Embodiment of the second invention) Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12
The figure is a diagram of a non-electrolyte solute concentration detection section (14), which is an embodiment of the second invention.
第７図、第８図、第９図、第１０図は、作用電極（１）
の表面とイオン感応部（３）の近傍に非電解質から電解
質を生成する物（１１）、例えば、酵素や微生物等の固
定化された膜が被覆されている非電解質の溶質濃度検出
部（１４〉の図である。Figures 7, 8, 9, and 10 show the working electrode (1)
A non-electrolyte solute concentration detection part (14) coated with a substance (11) that generates an electrolyte from a non-electrolyte, for example, a membrane in which enzymes, microorganisms, etc. are immobilized, is coated on the surface of the This is a diagram of
第１１図、第１２図は、イオン感応部（３）の表面とそ
の近傍に非電解質から電解質を生成する物（１１）、例
えば、酵素や微生物等の固定化された膜が被覆さ、れて
いる非電解質の溶質濃度検出部（１４）の図である。Figures 11 and 12 show that the surface of the ion-sensing part (3) and its vicinity are coated with a film in which an electrolyte is generated from a non-electrolyte (11), such as an enzyme or a microorganism immobilized thereon. FIG. 2 is a diagram of a non-electrolyte solute concentration detection unit (14).
第二発明による非電解質の濃度の測定実施例としてグル
コースの濃度測定結果を第１３図に示す。As an example of measuring the concentration of a non-electrolyte according to the second invention, the results of measuring the concentration of glucose are shown in FIG.
第１３図は、溶媒（１３）の脱イオン水にグルコース水
溶液を滴下した時の水槽中のグルコース濃度と濃度測定
Ｈ置の出力電圧である。FIG. 13 shows the glucose concentration in the water tank and the output voltage at the concentration measurement position H when an aqueous glucose solution is dropped into deionized water as the solvent (13).
第１図を用いて、グルコースの濃度測定実施例の測定回
路系を説明する。A measurement circuit system of an embodiment for measuring glucose concentration will be explained with reference to FIG.
溶媒（１３）、比較電極（１２〉、電解電圧は、第一発
明による過酸化水素の濃度測定実施例と同一である。The solvent (13), reference electrode (12), and electrolytic voltage are the same as in the hydrogen peroxide concentration measurement example according to the first invention.
溶質濃度の検出部（１４）は第１１図、第１２図の構造
である。非電解質から電解質を生成する物（１１）とし
て、非電解質のグルコースから電解質を生成するために
作用電極（１）またはイオン感応部（３）の近傍にグル
コースオキシダーゼを固定した。The solute concentration detection section (14) has the structure shown in FIGS. 11 and 12. As a product (11) for generating an electrolyte from a non-electrolyte, glucose oxidase was immobilized near the working electrode (1) or the ion-sensing part (3) in order to generate an electrolyte from the non-electrolyte glucose.
水溶液中のグルコースがグルコースオキシダーゼに触れ
るとこの触媒作用によってグルコースはグルコン酸と過
酸化水素に分解される。この過酸化水素の濃度はグルコ
ースの濃度に比例し、第一発明による過酸化水素の濃度
測定実施例と同様に、０．７Ｖの電圧が印加された作用
電極（１）に過酸化水素が触れると電気分解され、水素
イオンが生じる。この水素イオン濃度はグルコースの濃
度に比例し、水素イオン濃度の１５ＦＥＴ（２）による
検出値からグルコースの濃度が測定される。When glucose in an aqueous solution comes into contact with glucose oxidase, the catalytic action breaks down the glucose into gluconic acid and hydrogen peroxide. The concentration of hydrogen peroxide is proportional to the concentration of glucose, and as in the hydrogen peroxide concentration measurement example according to the first invention, hydrogen peroxide comes into contact with the working electrode (1) to which a voltage of 0.7V is applied. is electrolyzed, producing hydrogen ions. This hydrogen ion concentration is proportional to the glucose concentration, and the glucose concentration is measured from the hydrogen ion concentration detected by the 15FET (2).
グルコースオキシダーゼの触媒作用で生じるイオン濃度
を１５ＦＥＴで検出するにはイオン濃度が小さくグルコ
ース濃度の測定が困難であったが、第二の発明により、
第１３図のように高感度でその測定が可能になった。The ion concentration generated by the catalytic action of glucose oxidase was too small to be detected by a 15FET, making it difficult to measure the glucose concentration, but with the second invention,
As shown in Figure 13, it has become possible to measure this with high sensitivity.
（発明の効果）本願の第一の発明は、溶質の電離度を支配する電離定数
に左右されなく、電離定数の小さい溶質の低濃度測定限
界の下限を著しく下げることが可能になる。(Effects of the Invention) The first invention of the present application is not affected by the ionization constant that governs the degree of ionization of a solute, and it becomes possible to significantly lower the lower limit of the low concentration measurement limit for a solute with a small ionization constant.
第二の発明は、測定対象の非電解質の溶質から生成され
た電解質の定電位電解によって、測定対象溶質濃度に比
例して生じるイオン濃度のＴ ５ＦＥＴによる検出値か
ら測定される対象溶質の低濃度測定限界の下限を下げる
ことが可能になる。The second invention is a low concentration of a target solute, which is measured from a value detected by a T5FET of an ion concentration generated in proportion to the concentration of a solute to be measured by constant potential electrolysis of an electrolyte generated from a non-electrolyte solute to be measured. It becomes possible to lower the lower limit of measurement.
第１図は溶質濃度測定装置の回路図第２図は電解質の溶質濃度検出部の正面図第３図は電解
質の溶質濃度検出部の２−２”断面図第４図は電解質の溶質濃度検出部の正面図第５図は電解
質の溶質濃度検出部の４−４′断面図第６図は過酸化水素の濃度測定結果第７図は非電解質の溶質濃度検出部の正面図第８図は非
電解質の溶質濃度検出部の７−７′断面図第９図は非電解質の溶質濃度検出部の正面図第１０図は
非電解質の溶質濃度検出部の９−９′断面図第１１図は非電解質の溶質濃度検出部の正面図第１２図は非電解質の溶質濃度検出部の１１−１１’断
面図第１３図はグルコースの濃度測定結果Figure 1 is a circuit diagram of the solute concentration measuring device. Figure 2 is a front view of the electrolyte solute concentration detection section. Figure 3 is a 2-2" cross-sectional view of the electrolyte solute concentration detection section. Figure 4 is the electrolyte solute concentration detection section. Figure 5 is a 4-4' sectional view of the electrolyte solute concentration detection unit. Figure 6 is the hydrogen peroxide concentration measurement results. Figure 7 is a front view of the non-electrolyte solute concentration detection unit. FIG. 9 is a front view of the non-electrolyte solute concentration detection section. FIG. 10 is a 9-9' cross-section of the non-electrolyte solute concentration detection section. Figure 12 is a front view of the non-electrolyte solute concentration detection unit. Figure 12 is a 11-11' sectional view of the non-electrolyte solute concentration detection unit. Figure 13 is the glucose concentration measurement results.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2072994AJPH07119737B2 (en) | 1990-03-22 | 1990-03-22 | Solute concentration measuring device |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2072994AJPH07119737B2 (en) | 1990-03-22 | 1990-03-22 | Solute concentration measuring device |
| Publication Number | Publication Date |
|---|---|
| JPH03272449Atrue JPH03272449A (en) | 1991-12-04 |
| JPH07119737B2 JPH07119737B2 (en) | 1995-12-20 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2072994AExpired - Fee RelatedJPH07119737B2 (en) | 1990-03-22 | 1990-03-22 | Solute concentration measuring device |
| Country | Link |
|---|---|
| JP (1) | JPH07119737B2 (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7488405B2 (en) | 2003-12-15 | 2009-02-10 | Fuji Xerox Co., Ltd. | Electrode for electrochemical measurement and method for manufacturing the same |
| US7573186B2 (en) | 2003-12-15 | 2009-08-11 | Fuji Xerox Co., Ltd. | Electrode for electrochemical measurement |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7488405B2 (en) | 2003-12-15 | 2009-02-10 | Fuji Xerox Co., Ltd. | Electrode for electrochemical measurement and method for manufacturing the same |
| US7573186B2 (en) | 2003-12-15 | 2009-08-11 | Fuji Xerox Co., Ltd. | Electrode for electrochemical measurement |
| Publication number | Publication date |
|---|---|
| JPH07119737B2 (en) | 1995-12-20 |
| Publication | Publication Date | Title |
|---|---|---|
| JPS6283649A (en) | blood sugar meter | |
| US20070114137A1 (en) | Residual chlorine measuring method and residual chlorine measuring device | |
| Sohn et al. | ISFET glucose and sucrose sensors by using platinum electrode and photo-crosslinkable polymers | |
| US5387328A (en) | Bio-sensor using ion sensitive field effect transistor with platinum electrode | |
| US7323091B1 (en) | Multimode electrochemical sensing array | |
| JPH05503580A (en) | Polarographic chemical sensor with external reference electrode | |
| GB2520753A (en) | Electrochemical sensor apparatus and electrochemical sensing method | |
| CN110753840A (en) | Residual chlorine measuring method and residual chlorine measuring device | |
| US7087150B2 (en) | Chloramine amperometric sensor | |
| WO2020091033A1 (en) | Triple-pole electrode having electrically conductive diamond electrode as reference electrode, device, and electrochemical measuring method | |
| US4839000A (en) | Buffer compensation in enzyme-modified ion sensitive devices | |
| JPS638423B2 (en) | ||
| Hahn et al. | The development of new microelectrode gas sensors: an odyssey. Part 1. O2 and CO2 reduction at unshielded gold microdisc electrodes | |
| EP0345347A1 (en) | Fet electrode | |
| Colombo et al. | Coulometric micro-titrator with a ruthenium dioxide pH-electrode | |
| US20070000778A1 (en) | Multi-parameter sensor with readout circuit | |
| US3960673A (en) | Technique for continuously analyzing the concentration of ozone dissolved in water | |
| CN109239144A (en) | Current mode chlorine dioxide sensor | |
| US20060163088A1 (en) | Amperometric sensor with counter electrode isolated from fill solution | |
| JPH03272449A (en) | Solute concentration measuring apparatus | |
| WO1982001772A1 (en) | Reference electrode | |
| JPH09178700A (en) | Amperometric two-electrode sensor and measuring method with this sensor | |
| Trapp et al. | Development of a coulometric CO2 gas sensor | |
| Hendrikse et al. | The EMOSFET as a potentiometric transducer in an oxygen sensor | |
| Anh et al. | Electroactive gate materials for a hydrogen peroxide sensitive/sup E/MOSFET |
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |