JPH03237350A - Ph sensor and production thereof - Google Patents
Ph sensor and production thereofInfo
- Publication number
- JPH03237350A JPH03237350A JP2033198A JP3319890A JPH03237350A JP H03237350 A JPH03237350 A JP H03237350A JP 2033198 A JP2033198 A JP 2033198A JP 3319890 A JP3319890 A JP 3319890A JP H03237350 A JPH03237350 A JP H03237350A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- sensor
- carbon dioxide
- hydrogen ion
- ion
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 claims abstract description 35
- 239000012528 membrane Substances 0.000 claims description 42
- 239000000243 solution Substances 0.000 claims description 19
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims description 13
- 229910021607 Silver chloride Inorganic materials 0.000 claims description 12
- 229910052709 silver Inorganic materials 0.000 claims description 12
- 239000004332 silver Substances 0.000 claims description 12
- 239000007853 buffer solution Substances 0.000 claims description 7
- 239000006174 pH buffer Substances 0.000 claims description 7
- 238000001035 drying Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000004094 surface-active agent Substances 0.000 claims description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 abstract description 68
- 239000001569 carbon dioxide Substances 0.000 abstract description 34
- 229910002092 carbon dioxide Inorganic materials 0.000 abstract description 34
- 150000002500 ions Chemical class 0.000 abstract description 25
- 239000007788 liquid Substances 0.000 abstract description 22
- 238000005259 measurement Methods 0.000 abstract description 15
- 239000000872 buffer Substances 0.000 abstract description 7
- 239000000853 adhesive Substances 0.000 abstract description 3
- 230000001070 adhesive effect Effects 0.000 abstract description 3
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 abstract description 3
- 239000000463 material Substances 0.000 abstract description 3
- 229910019142 PO4 Inorganic materials 0.000 abstract description 2
- GTKRFUAGOKINCA-UHFFFAOYSA-M chlorosilver;silver Chemical compound [Ag].[Ag]Cl GTKRFUAGOKINCA-UHFFFAOYSA-M 0.000 abstract description 2
- 230000002209 hydrophobic effect Effects 0.000 abstract description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 abstract description 2
- 239000010452 phosphate Substances 0.000 abstract description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 12
- 239000011521 glass Substances 0.000 description 9
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 8
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 239000000126 substance Substances 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- -1 hydrogen ions Chemical class 0.000 description 4
- 235000017557 sodium bicarbonate Nutrition 0.000 description 4
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 4
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003822 epoxy resin Substances 0.000 description 3
- 239000012466 permeate Substances 0.000 description 3
- 229920000647 polyepoxide Polymers 0.000 description 3
- 229920000915 polyvinyl chloride Polymers 0.000 description 3
- 239000004800 polyvinyl chloride Substances 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000013060 biological fluid Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229940096810 diethylhexyl sebacate Drugs 0.000 description 2
- VJHINFRRDQUWOJ-UHFFFAOYSA-N dioctyl sebacate Chemical compound CCCCC(CC)COC(=O)CCCCCCCCC(=O)OCC(CC)CCCC VJHINFRRDQUWOJ-UHFFFAOYSA-N 0.000 description 2
- 230000005669 field effect Effects 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910001510 metal chloride Inorganic materials 0.000 description 2
- 238000001139 pH measurement Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 235000002639 sodium chloride Nutrition 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- SWZDQOUHBYYPJD-UHFFFAOYSA-N tridodecylamine Chemical compound CCCCCCCCCCCCN(CCCCCCCCCCCC)CCCCCCCCCCCC SWZDQOUHBYYPJD-UHFFFAOYSA-N 0.000 description 2
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 229910021397 glassy carbon Inorganic materials 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- BLQJIBCZHWBKSL-UHFFFAOYSA-L magnesium iodide Chemical group [Mg+2].[I-].[I-] BLQJIBCZHWBKSL-UHFFFAOYSA-L 0.000 description 1
- 229910001641 magnesium iodide Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000008363 phosphate buffer Substances 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920005597 polymer membrane Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002516 radical scavenger Substances 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は、各種の溶液や生体液中の水素イオン濃度を電
気化学的に測定するイオン選択性電極に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion-selective electrode for electrochemically measuring hydrogen ion concentrations in various solutions and biological fluids.
［従来の技術］
溶液の水素イオン濃度を測定するｐＨセンサーにはガラ
ス電極を用いたものが広く用いられている。ｐＨの測定
に使用されるガラス電極は、薄い水素イオン感応性ガラ
ス膜とその内部に内部基準液と銀・塩化銀電極等の内部
参照電極を有する。[Prior Art] pH sensors that use glass electrodes are widely used to measure the hydrogen ion concentration of a solution. The glass electrode used for pH measurement has a thin hydrogen ion-sensitive glass membrane, an internal standard liquid, and an internal reference electrode such as a silver/silver chloride electrode inside the membrane.
この電極はガラス膜の両側の水素イオン濃度の差によっ
て発生する膜電位を、内部参照電極と測定液中の基準電
極を用いて計測している。This electrode measures the membrane potential generated by the difference in hydrogen ion concentration on both sides of the glass membrane using an internal reference electrode and a standard electrode in the measurement solution.
ところが、ガラス電極は薄いガラス膜を使用しているた
めに機械的衝撃に弱く、またセンサ一部分を小さくする
と電気抵抗が大きくなり、測定には入力インピーダンス
が大きな電位差計が必要となる。入力インピーダンスが
高い系での測定は外部の電気的な雑音の影響を受は易く
、各種の装置が作動している環境での生体内液を対象と
した測定には問題があった。However, since the glass electrode uses a thin glass film, it is susceptible to mechanical shock, and if a portion of the sensor is made smaller, the electrical resistance increases, and measurement requires a potentiometer with a large input impedance. Measurements in systems with high input impedance are easily affected by external electrical noise, and there are problems with measurements of biological fluids in environments where various devices are operating.
このため、近年ではガラス電極よりも電気抵抗が低く、
小型化が可能で製造コストが低い、高分子物質の膜にイ
オン選択性の液体物質を坦持した液膜をガラス膜に代え
たｐＨセンサーが広く研究されている（Ａｎａｌｙｔｌ
ｃａ Ｃｈｌｍｌｃａ Ａｃｔａ、１９８１年第１３１
巻第１１１〜目６頁参照）。For this reason, in recent years, the electrical resistance is lower than that of glass electrodes.
pH sensors that can be miniaturized and have low manufacturing costs have been widely researched in which a glass membrane is used instead of a liquid membrane in which an ion-selective liquid substance is supported on a polymer membrane (Analytl.
ca Chlmlca Acta, 1981 No. 131
(See Vol. 111-Page 6).
また、これらの液膜型イオンセンサーの特性の改善も多
く提案されている。例えばイオンセンサーの検出電位の
安定化を図るために内部参照電極とイオン選択性の液膜
の間に、金属の塩化物を親水性のバインダーに分散した
層（特開昭５２−１４２５８４号）あるいは金属の塩化
物のみの層（特開昭ｆｌｉｐ−２３７３５１号）を設け
た例も報告されている。Furthermore, many proposals have been made to improve the characteristics of these liquid film type ion sensors. For example, in order to stabilize the detection potential of an ion sensor, a layer in which metal chloride is dispersed in a hydrophilic binder is placed between the internal reference electrode and the ion-selective liquid membrane (Japanese Patent Application Laid-open No. 142584/1984), or An example in which a layer consisting only of metal chloride (Japanese Patent Application Laid-open No. 237351/1999) has also been reported.
［発明が解決しようとする課題］
しかしながら、このような従来の技術にあっては、使用
する液膜の物質が測定対象のイオンのみではなく被検液
中に共存する他のイオン種によっても影響を受けて正確
な測定ができないという問題があった。例えば、被検液
中に二酸化炭素が溶解すると溶解した二酸化炭素がイオ
ン感応膜を透過し内部参照電極に達するとイオンセンサ
ーの種類によっては著しく測定電位が変動し、測定が不
可能となることがあった。[Problem to be solved by the invention] However, in such conventional techniques, the material of the liquid film used is affected not only by the ions to be measured but also by other ion species coexisting in the sample liquid. There was a problem that accurate measurements could not be made due to the For example, when carbon dioxide is dissolved in the test liquid, if the dissolved carbon dioxide passes through the ion-sensitive membrane and reaches the internal reference electrode, the measurement potential may vary significantly depending on the type of ion sensor, making measurement impossible. there were.
この内、酸化ケイ素及びアルミナからなるＦＥＴのゲー
ト絶ａ膜上にイオン選択性液膜を成膜したｌ５ＦＥＴ型
のカリウムイオン濃度センサーについての溶存二酸化炭
素の問題については、Ａｎａｌｙｓｔ １９８８年第１
１３巻１０２９〜１０３３頁に示されている。Regarding the problem of dissolved carbon dioxide in the 15FET type potassium ion concentration sensor, which has an ion-selective liquid film formed on the FET gate insulation film made of silicon oxide and alumina, see Analyst 1988, Vol.
13, pp. 1029-1033.
しかしながら、溶液中の二酸化炭素の濃度変化によって
生じるｐＨの変化を安定して測定できるｐＨセンサーに
ついては報告されていなかった。However, there has been no report on a pH sensor that can stably measure changes in pH caused by changes in the concentration of carbon dioxide in a solution.
本発明は、二酸化炭素が溶液中に溶解しても溶液中のｐ
Ｈ変化を安定して測定できる液膜型ｐＨセンサーを提供
することを目的とする。In the present invention, even if carbon dioxide is dissolved in the solution, p in the solution is
An object of the present invention is to provide a liquid film type pH sensor that can stably measure H changes.
［課題を解決するための手段］
二酸化炭素による影響を防止するためには、二酸化炭素
の透過を妨げる手段を設けること、あるいは二酸化炭素
が透過しても水素イオン濃度の測定値に影響を与えない
手段をとることが考えられるが、本発明者らは、透過し
た溶存二酸化炭素によって水素イオン濃度の測定値が変
動を受けない手段を鋭意検討した結果、溶存した二酸化
炭素が電極に到達しても正確に水素イオン濃度が測定で
きる手段を見いだしたものである。[Means for solving the problem] In order to prevent the effects of carbon dioxide, it is necessary to provide a means to prevent the permeation of carbon dioxide, or to have a method that does not affect the measured value of hydrogen ion concentration even if carbon dioxide permeates. However, as a result of intensive study by the present inventors on methods that would prevent the measured value of hydrogen ion concentration from being affected by the permeated dissolved carbon dioxide, we found that even if dissolved carbon dioxide reaches the electrode, They have discovered a means to accurately measure hydrogen ion concentration.
すなわち、水素イオン感応性の液膜を使用したｐＨセン
サーでは水素イオン感応膜の内部と外部の水素イオン濃
度の差によって生ずる膜電位を電位差計で測定している
が、溶存した二酸化炭素の透過によってイオン感応膜の
内部での水素イオン濃度が変化しない手段を設けること
によって測定した電位差に影響を及ぼさないようにした
ものであり、このために水素イオン感応膜と内部参照電
極との間に水素イオン感応膜を透過した溶存二酸化炭素
によって水素イオン濃度が変化することを防止する含水
時のｐＨ＝１〜８の緩衝層を内部参照電極表面に設けた
ものである。In other words, a pH sensor using a hydrogen ion-sensitive liquid membrane uses a potentiometer to measure the membrane potential caused by the difference in hydrogen ion concentration between the inside and outside of the hydrogen ion-sensitive membrane. By providing a means that does not change the hydrogen ion concentration inside the ion-sensitive membrane, it is possible to prevent the measured potential difference from being affected. A buffer layer having a pH of 1 to 8 when containing water is provided on the surface of the internal reference electrode to prevent the hydrogen ion concentration from changing due to dissolved carbon dioxide that has passed through the sensitive membrane.
ｐＨの緩衝液層は被検液中の二酸化炭素が水素イオン感
応膜を透過して、内部基準電極と該水素イオン感応膜間
に浸透した液と反応して発生した水素イオンがイオン感
応膜で発生するＭｇＩ２位の変化を防止し、溶存した二
酸化炭素による影響を受けずに水素イオン濃度を正確に
測定することが可能となるので、溶存した二酸化炭素が
反応して生じる水素イオン濃度を測定して二酸化炭素の
濃度を測定する原理を利用した二酸化炭素ガスセンサー
に本発明のｐＨセンサーを適用することも可能である。In the pH buffer layer, carbon dioxide in the test solution permeates the hydrogen ion sensitive membrane, and hydrogen ions generated by reacting with the liquid that has penetrated between the internal reference electrode and the hydrogen ion sensitive membrane pass through the ion sensitive membrane. It is possible to prevent the change in the MgI2 position that occurs and to accurately measure the hydrogen ion concentration without being affected by dissolved carbon dioxide. It is also possible to apply the pH sensor of the present invention to a carbon dioxide gas sensor that uses the principle of measuring the concentration of carbon dioxide.
すなわち、このよつなガスセンサーは二酸化炭素ガスを
選択的に透過する膜を介して内部液の炭酸水素ナトリウ
ム水溶液中に二酸化炭素を溶解させ、溶存した二酸化炭
素ガスとの反応の結果溶存した二酸化炭素濃度に対応し
て生じる水素イオン濃度を測定することにより二酸化炭
素ガスを測定することを原理としている。本発明のｐＨ
センサーを二酸化炭素ガスセンサーにおける炭酸水素ナ
トリウム水溶液中の水素イオン濃度の測定電極として使
用すれば、透過した二酸化炭素によって生じる水素イオ
ン濃度の変化を正確に測定することが可能である。In other words, this type of gas sensor dissolves carbon dioxide in an internal sodium bicarbonate aqueous solution through a membrane that selectively permeates carbon dioxide gas, and as a result of the reaction with the dissolved carbon dioxide gas, dissolved carbon dioxide is dissolved. The principle is to measure carbon dioxide gas by measuring the hydrogen ion concentration that occurs in response to the carbon concentration. pH of the invention
If the sensor is used as an electrode for measuring hydrogen ion concentration in an aqueous sodium bicarbonate solution in a carbon dioxide gas sensor, it is possible to accurately measure changes in hydrogen ion concentration caused by permeated carbon dioxide.
本発明のｐＨセンサーに使用する内部参照電極は通常の
銀・塩化銀電極に限らず電界効果トランジスタ（ＦＥＴ
）のゲート絶縁膜上に内部電極として銀・塩化銀電極を
形成したものを使用することも可能であり、またＦＥＴ
ゲート絶縁膜上に銀−塩化銀電極などの内部参照電極を
設けた後にｐＨ緩衝層を設け、その表面に水素イオン選
択性物質を含有したイオン選択性膜を接着し、同時にｐ
Ｈ測定電極の対極として作用する基準電極も電界効果ト
ランジスタのゲート絶縁膜上に銀・塩化銀電極等を半導
体製造技術を利用して製造することによって、極めて小
型のｐＨセンサーを得ることができる。The internal reference electrode used in the pH sensor of the present invention is not limited to ordinary silver/silver chloride electrodes, but also field-effect transistors (FETs).
) It is also possible to use a structure in which a silver/silver chloride electrode is formed as an internal electrode on the gate insulating film of the FET.
After providing an internal reference electrode such as a silver-silver chloride electrode on the gate insulating film, a pH buffer layer is provided, and an ion-selective film containing a hydrogen ion-selective substance is adhered to the surface of the pH buffer layer.
An extremely small pH sensor can be obtained by manufacturing a reference electrode, which acts as a counter electrode to the H measuring electrode, using a silver/silver chloride electrode or the like on the gate insulating film of the field effect transistor using semiconductor manufacturing technology.
［作用コ
内部参照電極上にｐＨ緩衝層を設けたので、水素イオン
感応膜を透過した溶存二酸化炭素によって水素イオン感
応膜に発生する膜電位が影響を受けないので、ｐＨ変化
に対してネルンスト式に従う電位の変化を示すので被検
液中に溶存二酸化炭素が存在していても正確な測定が可
能である。[Effect: Since a pH buffer layer is provided on the internal reference electrode, the membrane potential generated in the hydrogen ion sensitive membrane is not affected by dissolved carbon dioxide that has permeated through the hydrogen ion sensitive membrane. Since it shows a change in potential according to
また、選択透過性膜を透過した二酸化炭素が反応して生
じる水素イオンの濃度が溶存した二酸化炭素によって妨
害を受けることなく測定できる。Furthermore, the concentration of hydrogen ions produced by the reaction of carbon dioxide that has permeated through a selectively permeable membrane can be measured without being interfered with by dissolved carbon dioxide.
［実施例コ
以下、本発明の実施例を図面を参照して具体的に説明す
る。[Embodiments] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
第１図に本発明ｐＨセンサーの断面図を示す。FIG. 1 shows a cross-sectional view of the pH sensor of the present invention.
本発明のｐＨセンサーは、絶縁性の中空管ｌの内部に電
位差計と導電接続をするリード線２と結合したグラッシ
ーカーボンやグラフアイト等の導電性基体３がエポキシ
樹脂等の接着剤４によって取り付けられている。In the pH sensor of the present invention, a conductive substrate 3 such as glassy carbon or graphite is bonded to a lead wire 2 for conductive connection with a potentiometer inside an insulating hollow tube l, and an adhesive 4 such as epoxy resin installed.
導電性基体３には銀・塩化銀電極等の内部参照電極５が
設けられている。中空管の下端にはイオン選択性物質を
溶解した疎水性物質を担持したイオン感応膜６が設けら
れてあり、内部参照電極５とイオン感応膜との間には燐
酸塩の水溶液からなる緩衝液層７が設けられている。The conductive substrate 3 is provided with an internal reference electrode 5 such as a silver/silver chloride electrode. An ion-sensitive membrane 6 carrying a hydrophobic substance in which an ion-selective substance is dissolved is provided at the lower end of the hollow tube, and a buffer consisting of an aqueous phosphate solution is provided between the internal reference electrode 5 and the ion-sensitive membrane. A liquid layer 7 is provided.
実施例１，２
直径３０ ｍｖｓ、長さ２０．ＯｗｎのＰＶＣ製の中空
管の内部にリード線を導電性樹脂で接続したグラファイ
ト製（日本カーボン■製ＥＣ５１）の導電性基体をエポ
キシ樹脂（ブレースジャパン■製Ｃ−８５０−８）で接
着すると共に中空管の一方からは内部に液体等が入らな
いようにエポキシ樹脂を充填した。導電性基体には銀・
塩化銀電極を導電性接着剤（グレースジャバン■製Ｃ−
８５０−６）で接着した。Examples 1 and 2 Diameter 30 mvs, length 20 mvs. Glue a conductive base made of graphite (EC51 manufactured by Nippon Carbon ■) with a lead wire connected to the inside of the own PVC hollow tube using an epoxy resin (C-850-8 manufactured by Brace Japan ■). At the same time, one side of the hollow tube was filled with epoxy resin to prevent liquid from entering inside. The conductive substrate contains silver and
Connect the silver chloride electrode with conductive adhesive (C- manufactured by Grace Javan).
850-6).
銀・塩化銀電極にはｐＨが７．４及び４．０の燐酸緩衝
液各ＩＯ−厘をＩＯマイグロリフトルを滴下して乾燥し
た。On the silver/silver chloride electrode, phosphate buffer solutions with pHs of 7.4 and 4.0 were added dropwise to the IO migrolyttle and dried.
一方、水素イオン感応膜には、イオン選択性物質として
トリドデシルアミン６重量部、アニオン排除剤としてテ
トラキス（ｐ−クロロフェニル）硼酸カリウム０．６重
量部をセバシン酸ジエチルヘキシル６２重量部に溶解し
た液とポリ塩化ビニル３１重量部とをテトラヒドロフラ
ンを溶質１グラムに対して３ｍｌの割合で添加して溶解
した液からテトラヒドロフランを蒸発させて製膜した厚
さ０．８ｍｍの膜を使用し、緩衝液によって処理した内
部参照電極に間膜のテトラヒドロフラン溶液で接着した
。On the other hand, for the hydrogen ion-sensitive membrane, a solution was prepared by dissolving 6 parts by weight of tridodecylamine as an ion-selective substance and 0.6 parts by weight of potassium tetrakis(p-chlorophenyl)borate as an anion scavenger in 62 parts by weight of diethylhexyl sebacate. A film with a thickness of 0.8 mm was formed by evaporating tetrahydrofuran from a solution obtained by adding and dissolving 31 parts by weight of polyvinyl chloride in tetrahydrofuran at a ratio of 3 ml to 1 gram of solute. The membrane was adhered to the treated internal reference electrode with a solution of tetrahydrofuran.
得られたｐＨセンサーは一晩蒸留水中で膨潤しｐＨの測
定に使用した。The obtained pH sensor was swollen in distilled water overnight and used for pH measurement.
ｐＨの測定は第２図に示す装置で行った。測定槽８には
被検液９として、５ｍＭの炭酸水素ナトリウム水溶液を
用いた。本発明のｐＨセンサー１０と食塩を電解液とし
た銀・塩化銀電極からなる基準電極１１を電位差計（ア
トパンテスト社製ＴＲ８８４Ｂ） １２に接続した。比
較のために被検液中にはガラス電極１３と基準電極１４
を設けて同様の電位差計１５に接続した。被検液中には
二酸化炭素を溶解させてｐＨを変化させた。測定槽中の
被検液は撹拌手段１６によって組成が均一となるように
してｐＨに対する発生電位を測定した。また、この測定
は測定槽を恒温槽中で３７℃に保持して行った。The pH was measured using the apparatus shown in FIG. In the measurement tank 8, a 5 mM aqueous sodium hydrogen carbonate solution was used as the test liquid 9. The pH sensor 10 of the present invention and a reference electrode 11 consisting of a silver/silver chloride electrode using common salt as an electrolyte were connected to a potentiometer (TR884B manufactured by Atopan Test Co., Ltd.) 12. For comparison, a glass electrode 13 and a reference electrode 14 were included in the test liquid.
was connected to a similar potentiometer 15. Carbon dioxide was dissolved in the test liquid to change the pH. The test liquid in the measurement tank was made uniform in composition by stirring means 16, and the generated potential with respect to pH was measured. Further, this measurement was carried out while the measurement tank was maintained at 37° C. in a constant temperature bath.
この測定により表１に示す結果が得られた。The results shown in Table 1 were obtained from this measurement.
（以下余白）
表１ 各ｐＨセンサー感度（ｗ＋Ｖ／ｐＨａｔ３７℃）
この表からは、ｐＨが４．０の緩衝液を使用したものは
ネルンストの式に合致した特性を示すことがわかる。(Left below) Table 1 Sensitivity of each pH sensor (w+V/pHat37℃)
From this table, it can be seen that those using a buffer solution with a pH of 4.0 exhibit characteristics consistent with Nernst's equation.
また、第５図はりＨ全センサー経時変化を示したもので
、Ａは実施例２、Ｂは比較例に対するものである。In addition, FIG. 5 shows changes over time for all the beam H sensors, where A is for Example 2 and B is for Comparative Example.
実施例３． ４． ５
トリドデシルアミン０．２ｇ、 テトラキス（ｐ−ク
ロロフェニル）硼酸カリウム０．０２ｇ１ セバシン酸
ジエチルヘキシル０．５ｇ、 ポリ塩化ビニル１．０
ｇ１ テトラヒドロフラン１０ｍ１からなるイオン選
択透過性物質の溶液とｐＨが４． ０のリン酸を含む緩
衝液を、界面活性剤として東京化成工業−より販売され
ている商品名スパン８゜を０．０３ｇを用いて混合した
液を、内部参照電極上に該緩衝液を滴下乾燥後実施例１
と同様に水素イオン感応膜を接着し一晩膨潤後実施例１
と同様なｐＨ応答評価を行ったところ表２のようにネル
ンストの式に従う良好な感度を示した。Example 3. 4. 5 Tridodecylamine 0.2g, potassium tetrakis(p-chlorophenyl)borate 0.02g1 diethylhexyl sebacate 0.5g, polyvinyl chloride 1.0
g1 A solution of an ion selectively permeable substance consisting of 10 ml of tetrahydrofuran and a solution with a pH of 4. A buffer solution containing 0% phosphoric acid was mixed with 0.03 g of Span 8°, a product sold by Tokyo Kasei Kogyo as a surfactant, and the buffer solution was dropped onto the internal reference electrode. Example 1 after drying
Example 1 After adhering a hydrogen ion sensitive membrane and swelling it overnight in the same manner as in Example 1.
When pH response evaluation was performed in the same manner as in Table 2, good sensitivity according to Nernst's equation was shown.
表２ ｐＨセンサー感度（３７℃）
実施例６
第３図に示すように、シリコーン、ポリカーボネート、
ポリウレタンを重量比で！００ ： １２．５ ：１２
．５からなる膜厚３０μｍの膜を二酸化炭素選択透過性
膜１７、実施例１のｐＨセンサー１ｏ１ 銀・塩化銀電
極の基準電極１８、銀線からなるコモン電極１９をハウ
ジング２０に取り付け、ハウジング内には５ミリモルの
炭酸水素ナトリウムと１５０−翼の塩化ナトリウム及び
飽和塩化銀水溶液２１を内包した３電極法の二酸化炭素
センサーを製造して、二酸化炭素濃度を測定したところ
、二酸化炭素分圧が３８１ｍ１１ｇから７０−−ＩＩｇ
までの濃度を正確に測定することができた。Table 2 pH sensor sensitivity (37°C) Example 6 As shown in Figure 3, silicone, polycarbonate,
Polyurethane by weight ratio! 00:12.5:12
．． A carbon dioxide selectively permeable membrane 17, a reference electrode 18 of the pH sensor 1o1 silver/silver chloride electrode of Example 1, and a common electrode 19 made of a silver wire are attached to the housing 20, and a membrane with a thickness of 30 μm consisting of 5 is attached to the housing 20. manufactured a carbon dioxide sensor using a three-electrode method containing 5 mmol of sodium hydrogen carbonate, 150-winged sodium chloride, and a saturated silver chloride aqueous solution, and measured the carbon dioxide concentration, and found that the partial pressure of carbon dioxide was from 381 m11 g. 70--IIg
We were able to accurately measure the concentration up to
実施例７
半導体製造技術を用いてＭＯＳＦＥＴのゲート電極をイ
オン感応膜で構成し、測定液中のイオン濃度が変化する
と溶液とイオン感応膜界面の界面電位が変化し、それに
より半導体表面のチャンネルの導電率が変化するという
原理を利用したｌ５ＦＥＴを基体とした点以外は上記実
施例１と同じ条件でｐＨ測定電極を作成した。Example 7 The gate electrode of a MOSFET is constructed with an ion-sensitive membrane using semiconductor manufacturing technology, and when the ion concentration in the measurement solution changes, the interfacial potential at the interface between the solution and the ion-sensitive membrane changes, which causes the channel on the semiconductor surface to change. A pH measuring electrode was prepared under the same conditions as in Example 1 above, except that the substrate was an 15FET that utilized the principle of changing conductivity.
第４図は、イオン感応部のＦＥＴを示すｌ５ＦＥＴの断
面図を示すが、ｌ５ＦＥＴはｓｏｓ ｃシリコン・オン
・サファイア）基板２２の表面に構成されている。FIG. 4 shows a cross-sectional view of the 15FET showing the FET of the ion sensitive section, which is constructed on the surface of the SOS (silicon on sapphire) substrate 22.
シリコン層２３にはソース領域２４とドレイン領域２５
が設けられ、その上にはシリコン酸化膜２６が形成され
、シリコン酸化膜上にはＦＥＴのゲート絶縁膜あるいは
金属膜２７が形成されていゲート絶縁膜上には銀・塩化
銀電極２８がその上にはｐＨのａ新暦２９を介して水素
イオン選択透過性膜３０が形成されている。The silicon layer 23 has a source region 24 and a drain region 25.
A silicon oxide film 26 is formed thereon, a gate insulating film or metal film 27 of the FET is formed on the silicon oxide film, and a silver/silver chloride electrode 28 is formed on the gate insulating film. A hydrogen ion permselective membrane 30 is formed through a pH filter 29 .
以上のような水素イオン選択透過性膜を有するｌ５ＦＥ
Ｔとともに基準電極ＦＥＴを同一の基板上に設けて両者
の差動出力を検出して測定する小型の素子を製造するこ
とも可能である。15FE having a hydrogen ion permselective membrane as described above
It is also possible to manufacture a small element that provides a reference electrode FET and a reference electrode FET on the same substrate and detects and measures the differential output between the two.
［発明の効果］
電極と該電極を被覆する水素イオン感応膜とからなるｐ
Ｈセンサーであって、該電極の表面にはｐＨの緩衝層を
設けたことにより、測定液中の溶存二酸化炭素の影響を
受けずｐＨの測定が可能となる。[Effect of the invention] A p-type film consisting of an electrode and a hydrogen ion-sensitive membrane covering the electrode.
By providing a pH buffer layer on the surface of the electrode of the H sensor, pH can be measured without being affected by dissolved carbon dioxide in the measurement liquid.
ｐＨの緩衝層含水時のｐＨが１〜８の範囲であることに
より、経時的に安定したｐＨセンサーが提供できる。When the pH of the buffer layer is in the range of 1 to 8 when it contains water, a pH sensor that is stable over time can be provided.
電極が銀・塩化銀電極であることにより応答特性のよい
ｐＨセンサーが提供できる。Since the electrode is a silver/silver chloride electrode, a pH sensor with good response characteristics can be provided.
電極に所定のｐＨ１所定の濃度の緩衝液を滴下乾燥後、
水素イオン透過膜を接着することにより容易に１）Ｈセ
ンサーが製造される。A buffer solution with a predetermined pH and a predetermined concentration is dropped onto the electrode, and after drying,
1) An H sensor is easily manufactured by adhering a hydrogen ion permeable membrane.
緩衝液と水素イオン透過膜成分を界面活性剤を用いて溶
解し、該液を電極に滴下乾燥後、水素イオン透過膜を接
着することにより、強固に水素イオン透過膜が剥離しに
くいｐＨセンサーが製造される。By dissolving the buffer solution and the hydrogen ion permeable membrane components using a surfactant, dropping the solution onto the electrode, and drying, the hydrogen ion permeable membrane is adhered to create a pH sensor with a strong hydrogen ion permeable membrane that is difficult to peel off. Manufactured.
第１図は本発明のｐＨセンサーの断面図を示す図、第２
図は本発明のｐＨセンサーの特性を測定する装置を示す
図、第３図は本発明のｐＨセンサーを使用した二酸化炭
素ガスセンサーの構成例を示す図、第４図は本発明のｐ
Ｈセンサーをｌ５ＦＥＴに適用した図、第５図は緩衝液
層の有無と測定値の変動を示す図である。
内部参照電極・・５
イオン感応膜・・６
緩衝液の含浸部・７Figure 1 is a cross-sectional view of the pH sensor of the present invention, Figure 2 is a diagram showing a cross-sectional view of the pH sensor of the present invention.
The figure shows an apparatus for measuring the characteristics of the pH sensor of the present invention, Figure 3 shows an example of the configuration of a carbon dioxide gas sensor using the pH sensor of the present invention, and Figure 4 shows the pH sensor of the present invention.
FIG. 5 is a diagram in which the H sensor is applied to a 15FET, and shows the presence or absence of a buffer layer and fluctuations in measured values. Internal reference electrode...5 Ion-sensitive membrane...6 Buffer impregnated part...7
Claims (5)
なるｐＨセンサーであって、該電極の表面にはｐＨの緩
衝層を設けたことを特徴とするｐＨセンサー。(1) A pH sensor comprising an electrode and a hydrogen ion sensitive membrane covering the electrode, characterized in that a pH buffer layer is provided on the surface of the electrode.
ることを特徴とする請求項１記載のｐＨセンサー。(2) The pH sensor according to claim 1, wherein the pH of the pH buffer layer when it contains water is in the range of 1 to 8.
求項１記載のｐＨセンサー。(3) The pH sensor according to claim 1, wherein the electrode is a silver/silver chloride electrode.
燥後、水素イオン透過膜を接着することを特徴とするｐ
Ｈセンサーの製造方法。(4) A p characterized in that a buffer solution of a predetermined pH and a predetermined concentration is dropped onto the electrode, and after drying, a hydrogen ion permeable membrane is adhered.
H sensor manufacturing method.
いて溶解し、該液を電極に滴下乾燥後、水素イオン透過
膜を接着することを特徴とするｐＨセンサー製造方法。(5) A method for manufacturing a pH sensor, which comprises dissolving a buffer solution and a hydrogen ion permeable membrane component using a surfactant, dropping the solution onto an electrode, drying it, and then adhering the hydrogen ion permeable membrane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2033198A JPH03237350A (en) | 1990-02-14 | 1990-02-14 | Ph sensor and production thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2033198A JPH03237350A (en) | 1990-02-14 | 1990-02-14 | Ph sensor and production thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03237350A true JPH03237350A (en) | 1991-10-23 |
Family
ID=12379785
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2033198A Pending JPH03237350A (en) | 1990-02-14 | 1990-02-14 | Ph sensor and production thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03237350A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013105449A1 (en) * | 2012-01-13 | 2013-07-18 | 国立大学法人東京大学 | Gas sensor |
| US9546948B2 (en) | 2012-01-13 | 2017-01-17 | The University Of Tokyo | Gas sensor |
-
1990
- 1990-02-14 JP JP2033198A patent/JPH03237350A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013105449A1 (en) * | 2012-01-13 | 2013-07-18 | 国立大学法人東京大学 | Gas sensor |
| JPWO2013105449A1 (en) * | 2012-01-13 | 2015-05-11 | 国立大学法人 東京大学 | Gas sensor |
| US9250210B2 (en) | 2012-01-13 | 2016-02-02 | The University Of Tokyo | Gas sensor |
| US9546948B2 (en) | 2012-01-13 | 2017-01-17 | The University Of Tokyo | Gas sensor |
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