KR101392666B1 - Composition for solid state ion-selective membrane electrodes and ion sensors manufactured from the same - Google Patents

Abstract

The present invention relates to a composition for manufacturing solid ion-selective membrane electrodes, wherein the composition includes a polymer matrix, a conductive polymer, and an ion carrier. The present invention can provide an ion-selective membrane with improved adhesion against a substrate and reduced membrane resistance. According to the present invention, a single-phase solid ion-selective membrane or an ion sensor is easily manufactured using the composition with improved adhesion against a substrate and the ion sensor provides stable signals and rapid response time and improves lifetime characteristics. Particularly, the present invention can be easily applied to a polymer matrix with high resistance like a silicone rubber.

Description

[0001] The present invention relates to a composition for the production of a solid-state ion-selective membrane electrode and an ion sensor manufactured therefrom,

The present invention relates to a composition for use in the preparation of solid phase ion selective membrane electrodes which have been used in a wide range of clinical, industrial and environmental analyzes, and ion sensors made therefrom.

Ion-Selective Membrane Electrodes (ISMEs) or Ion-Selective Electrodes (ISEs) are ion sensors that measure ions using potentiometry. Ion-Selective Membrane Electrodes (ISMEs) And measuring the potential difference generated by the charge separation formed on the surface of the film when the selective film is bonded to a specific ion or molecule to quantify the ions contained in the sample. In particular, the ion selective membrane electrode has advantages such as high selectivity for specific ions, short analysis time, and low cost of analysis, and thus can be applied to food chemistry, fermentation process, environmental analysis, hemodialysis, It is used for the measurement of ion species in various fields such as automatic measurement and clinical chemistry such as extracorporeal blood.

Ion-selective membrane electrodes can be divided into two types: conventional ion-selective membrane electrodes, which must have an internal filling solution between an ion-selective membrane and an internal reference electrode, selective membrane electrode and a solid-state ion-selective membrane electrode that does not require an internal filling solution. The advantage of solid-state ion selective membrane electrodes is that (1) internal filling solution is not required, so that the fabrication process can be simplified in manufacturing electrodes, and it is advantageous to miniaturize electrodes and various types of electrodes are easy to manufacture ; (2) It is easy to develop a multisensor capable of simultaneously detecting multiple ions in one chip; (3) It is advantageous to reduce production cost because mass production is possible; (4) It is possible to use a small amount of sample due to miniaturization of the sensitive part. In the case of a conventional ion selective membrane electrode, the ion selective membrane can be fixed on the electrode body to fix the ion selective membrane, but in the case of the solid phase electrode, the ion selective membrane is exposed without any stagnation on the electrode surface. The adhesive strength to the electrode serves as an important factor determining the life and electrochemical characteristics of the electrode.

One example of a recent attempt of a solid phase ion selective membrane electrode is to apply a redox and ion exchangeable layer of material such as a conductive polymer to generate a signal from the ion selective membrane with a readable electrical signal on the metal substrate. The application of the conductive polymer does not interfere with the charge transfer in the ion selective membrane-conductive polymer-metal substrate interface, thereby remarkably improving the redox capacity and obtaining stable sensor response. High conductivity, environmental friendliness, and a large number of conductive polymers that can be synthesized on an aqueous liquid or organic solvent have been utilized in the structure of ion selective membrane electrodes. The conductive polymer is introduced into the electrode by an electro-polymerization method or by using a conductive polymer soluble in an organic solvent. The conductive polymer is introduced into the hydration layer on the interface between the ion- Is prevented.

However, since the above-described attempts require a troublesome process in the structure of the sensor, a single-piece solid-state ion-selective electrode (SPASS-ISE) has recently been proposed.

In SPASS-ISE, a composition for preparing an ion-selective membrane including a polymer matrix, an ionophore, an additive, and a conductive polymer is prepared, and the resultant is drop-coated on the electrode on the substrate to complete the production of the sensor. In the fabrication of such a sensor, a film material (polymer matrix) having a high adhesive strength, a low membrane resistance, a homogeneous and highly conductive conductive polymer are required, and as a result, a sensor having excellent stability and life characteristics can be provided. The low stability of the sensor, especially in the fabrication of such sensors, is due to the polymer matrix with low adhesion. For example, poly (vinyl chloride) (PVC), a polymer matrix commonly used in the manufacture of ion selective membranes, falls off the substrate and reference electrode surface due to its weak adhesion properties. Therefore, the use of PVC in a SPASS-ISE manufacturing composition can not provide good results in the stability of the sensor. On the other hand, in the case of silicone rubber (SR), the adhesive strength is very excellent when used as a polymer matrix, but its high resistance causes a serious noise problem in the sensor signal. Therefore, it is urgent to develop a composition for producing SPASS-ISE having a strong adhesive force and a low membrane resistance.

1. J. Bobacka, Electroanalysis 18, 2006, No. 1, 7-18 "Conducting Polymer-Based Solid-State Ion-Selective Electrodes"
2. Johan Bobacka, Tom Lindfonr, Mary McCarrick, Ari Ivaska, Andrzej Lewenstam, Anal. Chem. 1995, 67, 3819-3823, "Single-Piece All-Solid-State Ion-Selective Electrode"
The above-mentioned prior art document 1 is a review article on an ion sensor in which a conductive polymer is located, and the preceding document 2 is a paper referred to in the prior art document 1.

The present invention relates to a composition for use in the preparation of solid-state ion selective membrane electrodes, which is selective for a number of ions including potassium ion (K ⁺ ), sodium ion (Na ⁺ ) or hydrogen ion (H ⁺ Which has high adhesion to a substrate and low film resistance.

The present invention also provides an ion sensor which is stable, has a short response time, and has excellent lifetime characteristics.

The present invention provides a composition for preparing a solid ion selective membrane electrode, which comprises a polymer matrix, an ionophore and a conductive polymer represented by the following formula 1 or 2:

[Formula 1]

[Formula 2]

Preferably, the polymer matrix is selected from the group consisting of poly (vinyl chloride), silicone rubber, polyurethane, poly (vinyl chloride) carboxylate, polyvinyl chloride aminate poly (vinyl chloride) aminate, poly (methylacrylate), poly (ethylene oxide), xerogel, and combinations thereof.

Preferably, the ion carrier is selected from the group consisting of potassium ions K ⁺ , sodium ions Na ⁺ , hydrogen ions H ⁺ , lithium ions Li ⁺ , rubidium ions Rb ⁺ , cesium ions Cs ⁺ (Mg ²⁺ ), calcium ions (Ca ²⁺ ), strontium ions (Sr ²⁺ ), barium ions (Ba ²⁺ ), copper ions (Cu ²⁺ ), silver ions (Ag ⁺ ), zinc ions ^2+), Cd ion (Cd ^2+), mercury ions (Hg ^2+), thallium ions (Tl ^+), lead ions (Pb ^2+), uranium oxide ion (UO ₂ ^2+), ion samarium (Sm ^{3 +),} ammonium ion (NH ₄ ^+), carbonate ions (CO ₃ ^2-), thiocyanate ion (SCN ^-), nitrite ion (NO ₂ ^-), hydroxide ions (OH ^-), phosphine ion (HPO ₄ ^{2 -),} hydrogen sulphide Oh ion (HSO ₃ ^-), sulfate ion (SO ₄ ^2-), chloride ion (Cl ^-), perchlorate ion (ClO ₄ ^-), iodine Chemistry ion (I ^-), iodide ion cedar ( I ₃ ^- ) and fluorine ion (F ^- ).

Preferably, the conductive polymer is contained in an amount of 0.1 to 4% by weight based on the entire composition.

Preferably, the composition comprises a solvent selected from the group consisting of CHCl ₃ , CH ₂ Cl ₂ , and tetrahydrofuran (THF).

Preferably, the amount of the solid component in the composition is in the range of 10 to 40% by weight.

Preferably, the composition comprises at least one compound selected from the group consisting of potassium tetrakis (4-chlorophenyl) borate (KT p ClPB), potassium tetrakis [3,5-bis (trifluoromethyl) 3,5-bis (trifluoromethyl) phenyl] borate (KTFPB), sodium tetrakis [3,5-bis (trifluoromethyl) phenyl] sodium tetrakis (4-fluorophenyl) borate dihydrate (NaT p FPB), sodium tetraphenylborate (NaTPB)), sodium tetrakis (4-fluorophenyl) Tetrabutylammonium tetraphenylborate (TBATPB), tridodecylmethylammonium chloride (TDMACl), tridodecylmethylammonium nitrate, tetraoctylammonium bromide e) tetradodecylammonium tetrakis (4-chlorophenyl) borate (ETH500), tetraheptylammonium tetraphenylborate (THATPB) and tetraphenylphosphonium tetraphenylborate And at least one additive selected from the group consisting of borate (Tetraphenylphosphonium tetraphenylborate (TPPTPB)).

The present invention provides an ion sensor comprising a silver / silver chloride electrode printed on a substrate and a working electrode comprising a drop-coated ion selective membrane over the silver / silver chloride electrode.

Preferably, the ion-selective membrane comprises 0.1 to 4% by weight of the conductive polymer expressed by the following formula 1 or 2, based on the total weight of the membrane:

[Formula 1]

[Formula 2]

Preferably, the ion selective membrane comprises a silicone rubber as a polymer matrix.

Preferably, the ion-selective membrane has a thickness of 100 to 300 mu m.

Preferably, in the ion sensor, the ion sensor is formed of at least one selected from the group consisting of potassium ion (K ⁺ ), sodium ion (Na ⁺ ), hydrogen ion (H ⁺ ), lithium ion (Li ⁺ ), rubidium ion (Rb ^{+ +),} magnesium ion (Mg ^2+), calcium ion (Ca ^2+), strontium ion (Sr ^2+), barium ion (Ba ^2+), copper ion (Cu ^2+), ion (Ag ^+), (Zn ²⁺ ), cadmium ion (Cd ²⁺ ), mercury ion (Hg ²⁺ ), thallium ion (Tl ⁺ ), lead ion (Pb ²⁺ ), uranium oxide (UO ₂ ²⁺ ) ion (Sm ^3+), ammonium ion (NH ₄ ^+), carbonate ions (CO ₃ ^2-), thiocyanate ion (SCN ^-), nitrite ion (NO ₂ ^-), hydroxide ions (OH ^-), phosphine ion (HPO ₄ ^2-), hydrogen sulfide Oh ion (HSO ₃ ^-), sulfate ion (SO ₄ ^2-), chloride ion (Cl ^-), perchlorate ion (ClO ₄ ^-), iodine Chemistry ion (I ^-), that the selectivity for the ion is selected from the group consisting of a tri iodide ion (I ₃ ^{- -),} and fluoride ion (F) The.

Preferably, the working electrode may be a disk electrode, a screen printing electrode, or a needle.

The composition for preparing a solid ion selective membrane electrode according to the present invention has an excellent adhesive force, and the bulk resistance of the bulk film produced therefrom is remarkably reduced. Therefore, in the ion sensor manufactured from the composition of the present invention, the noise level of the response signal is reduced, and it exhibits excellent sensitivity to specific ions, and is stable, has a quick response time, and has excellent life characteristics.

Also, when a sensor is manufactured from the composition for preparing an ion selective film of the present invention, the yield in production of a product showing a reliable response result is improved.

Fig. 1 shows the results of potentiometric titration of the examples and comparative sensors according to the potassium ion concentration.
Figure 2 compares the signal stability and the response time in the example and comparative sensor.
Figure 3 is a Nyquist plot for measuring membrane resistance in the example and comparative sensors.
Figure 4 compares the effect of surfactant over time in the example and comparative sensors.
FIGS. 5A to 5C are a plan view, a perspective view, and a cross-sectional view, respectively, of the working electrode manufactured in the embodiment of the present invention, and FIG.
6 shows an experimental configuration diagram for evaluating the potential difference titration.

Definition of Terms

The terms "ion selective membrane electrode", "electrode", "ion sensor" and "sensor" are used interchangeably unless otherwise noted.

The present invention provides a composition for use in the production of an ion selective membrane having a strong adhesion to a substrate for electrode preparation and a low membrane resistance to a specific ion as a composition for preparing a solid ion selective membrane electrode. As used herein, the term " membrane resistivity " is used to mean electrical resistance in a film on a bulk film in the range of 3 to 10 mm ² and the thickness of 100 to 300 μm produced from the composition of the present invention. When the electrical resistance of the ion-selective membrane is lowered, charge separation formed on the surface of the membrane by binding with specific ions or molecules can easily occur, so that it is possible to provide a sensor having a stable signal and a fast response time.

The composition of the present invention having the above properties can be usefully used in the fabrication of micro-ion sensors. Specifically, the composition of the present invention is characterized by comprising a polymer matrix, an ionophore, and a conductive polymer expressed by the following formula 1 or 2:

[Formula 1]

[Formula 2]

The conductive polymer remarkably lowers the resistance of a film (bulk) formed therefrom when it is applied to a polymer matrix having a particularly high film resistance. This is due to the fact that the polymer has a high electrical conductivity (polymer (SCPA) of 3.08 × 10 ^-3 S / cm 2 and polymer (SCPB) of 4.25 × 10 ^-3 S / cm). In addition, since they are well soluble in solvents, they result in homogeneous electrical signal behavior, ie, signal stability and fast response time, when applied to ion selective membranes of ion sensors, as described below.

As the polymer matrix included in the composition of the present invention, polyvinyl chloride, silicone rubber, polyurethane, poly (vinyl chloride) carboxylate, polyvinyl It is preferably selected from the group consisting of poly (vinyl chloride) aminate, poly (methylacrylate), poly (ethylene oxide), xerogel, and combinations thereof But not limited to, a polymer matrix used in the production of a solid-phase ion-selective membrane can be used without limitation. In particular, silicone rubber is a polymer matrix having strong adhesion, However, there are many difficulties in practical application. However, It is confirmed that the addition of the conductive polymer 1 or 2 significantly reduces the resistivity and thus shows a homogeneous signal behavior suitable for use as the ion sensor.

On the other hand, when conventional commercialized conductive polymers such as CHCl ₃ , CH ₂ Cl ₂ , and tetrahydrofuran (THF) are used for a polymer matrix having a high resistance such as silicone rubber, And thus exhibit heterogeneous behavior in the electrical signal. I.e. agglomerates in the composition, which interfere with the sensor's response, resulting in unstable signal and delayed response times. On the other hand, the conductive polymer included in the composition of the present invention exhibits homogeneous homogeneous behavior without forming agglomerates due to its high solubility in solvents as described above.

The conductive polymer is preferably contained in an amount of 0.1 to 4% by weight based on the total weight of the composition. If it is contained in an amount less than 0.1% by weight, it is difficult to distinguish the signal due to noise in the titration of the potential difference according to the ion concentration, and the time (response time) to reach a stable signal becomes too long. A signal for a desirable correct result is not obtained.

Next, the composition of the present invention includes an ion carrier. By way of example ionophore is potassium ions (K ^+), sodium ion (Na ^+), hydrogen ions (H ^+), lithium ions (Li ^+), rubidium ions (Rb ^+), cesium ion (Cs ^+), magnesium ion ( Mg ^2+), calcium ion (Ca ^2+), strontium ion (Sr ^2+), barium ion (Ba ^2+), copper ion (Cu ^2+), silver ions (Ag ^+), zinc ion (Zn ²⁺ ), cadmium ion (Cd ^2+), mercury ions (Hg ^2+), thallium ions (Tl ^+), lead ions (Pb ^2+), uranium oxide ion (UO ₂ ^2+), ion samarium (Sm ³⁺⁾ , ammonium ion (NH ₄ ^+), carbonate ions (CO ₃ ^2-), thiocyanate ion (SCN ^-), nitrite ion (NO ₂ ^-), hydroxide ions (OH ^-), phosphine ion (HPO ₄ ^2- ), Abu hydrogen sulfide ions (HSO ₃ ^-), sulfate ion (SO ₄ ^2-), chloride ion (Cl ^-), perchlorate ion (ClO ₄ ^-), iodine Chemistry ion (I ^-), three iodide ion (I ₃ ^- ) and fluorine ions (F < ^- >). The composition comprising the ion carrier is made of an ion selective membrane having selectivity for each ion. That is, various ion selective electrodes can be manufactured according to the ion carrier used. These ion carriers are preferably contained in an amount of 1 to 10% by weight based on the total composition. If it is contained in an amount less than the above range, the sensitivity and selectivity of the target ion are lowered and can not operate properly. If the ion carrier is contained in an amount larger than the above range, the amount of the polymer matrix in the drop- .

The composition of the present invention may also include potassium tetrakis (4-chlorophenyl) borate (KT p ClPB), potassium tetrakis [3,5-bis (trifluoromethyl) phenyl] borate 3,5-bis (trifluoromethyl) phenyl] borate (KTFPB), sodium tetrakis [3,5-bis (trifluoromethyl) phenyl] sodium tetrakis (4-fluorophenyl) borate dihydrate (NaT p FPB), sodium tetraphenylborate (NaTPB)), sodium tetrakis (4-fluorophenyl) Tetrabutylammonium tetraphenylborate (TBATPB), tridodecylmethylammonium chloride (TDMACl), tridodecylmethylammonium nitrate, tetraoctylammonium bromide, tetrabutylammonium bromide, Tetradodecylammonium tetrakis (4-chlorophenyl) borate (ETH500), tetraheptylammonium tetraphenylborate (THATPB), and tetraphenylphosphonium borate tetraphenylborate (TPPTPB)) may be further included. They are preferably added in an amount of 5 to 50 mol% based on the ion carrier, and when the ions enter the ion selective membrane from the bulk solution, an ion exchange site for maintaining the electrical neutrality of the ion selective membrane is provided, It facilitates accessibility and helps to generate potential difference. Any additives used in ion selective membranes can be used without limitation. 2-nitrophenyl octyl ether (NPOE), dioctyl sebacate (DOS), which is a plasticizer that gives flexibility of the ion selective membrane and helps the ion permeable carrier to better coordinate with ions ), Bis (2-ethylhexyl) phthalate (DOP), bis (2-ethylhexyl) adipate (DOA) And any plasticizer used in ion-selective membranes can be used without limitation.

The polymer matrix, conductive polymer, ion carrier and additives are dissolved in a solvent selected from the group consisting of CHCl ₃ , CH ₂ Cl ₂ , and tetrahydrofuran (THF). At this time, the amount of the total solid component in the solvent is preferably in the range of 10 to 40% by weight because it provides a composition having a viscosity favorable to a casting process for producing a film.

The composition of the present invention may be mounted in the manufacture of a solid phase ion selective membrane (working electrode) of an ion sensor. The working electrode may be a disk electrode, a screen printing electrode, or a needle. In one embodiment, an ion selective film is formed by a simple method of drop casting the composition onto a reference electrode printed on an alumina or polyester, polycarbonate substrate to produce a working electrode. Preferably, the ion-selective membrane has a thickness of 100 to 300 mu m. As the reference electrode, a silver / silver chloride electrode is used. Also, a silver / silver chloride electrode is used as an external electrode in the measurement of the potential difference for measuring the ion concentration contained in the sample. Such an ion sensor includes an ion selective film exhibiting high adhesiveness and low film resistance as described above, and thus has a stable signal and a fast response time. In addition, the production yield of the sensor is improved. In other words, when the sensor is manufactured from the same process, the defective incidence rate of the product is reduced, thereby making it possible to manufacture an effective sensor.

Hereinafter, the present invention will be described in more detail with reference to examples. However, this is for the purpose of helping understanding of the invention, and therefore the present invention should not be construed as being limited thereto.

Synthesis Example 1

To a 50 mL round bottom flask equipped with a condenser was added 15 mL of THF, 2,6-didodecyl-4,8-diethynyl-benzo [1,2-d: 4,5- d '] bisthiazole 0.3 g (5.20 x 10 ^-4 mol) of tetrakis (triphenylphosphine) palladium (Tetrakis (triphenyl) bis 0.04 g (0.044x10 ^-5 mol) of CuI (I), 0.01 g (0.078 mmol) of triethylamine and 6.4 mL (45.8 mmol) of triethylamine were added and stirred at 60 ° C. for 10 hours Respectively. It was then cooled and THF was removed using a rotary evaporator. A red-colored solid residue was obtained, which was purified by ethanol to obtain 35 g of a conductive polymer (SCPA) represented by the following formula. The yield was 71%.

[Formula 1]

^{1 H-NMR (400MHz, CDCl} 3): δ 4.12, 3.25, 1.97, 1.51, 1.34, 0.87 ppm

¹³ C-NMR (400 MHz, CDCl ₃ ): 隆 175.03, 153.84, 149.92, 138.18, 116.49, 113.78, 110.58, 91.06, 90.98, 77.57, 77.32, 77.21, 77.01, 76.69, 70.09, 69.60, 35.06, 31.92, 29.67, 29.62, 29.58, 29.46, 29.38, 29.29, 29.18, 29.04, 28.70, 26.14, 26.07, 22.70, 22.70, 14.16 ppm

IR (KBr): 2960, 2921, 2850, 2361, 2334, 2205, 1520, 1461, 1277, 1215, 1039 cm ^-1 .

The amount of the element obtained from the above results: C, 76.01; H, 9.32; _{N, 3.21 (C 60 H 90} N 2 O 2 amount of calculation for the _{S 2: C, 76.87; H} , 9.59; N, 2.99)

Weight average molecular weight (Mw): 4.8 X 10 ⁴

Number average molecular weight (Mn): 3.2 X 10 ⁴

Synthesis Example 2

To a 100 mL round bottom flask equipped with a condenser was added 2.10 g (4.65 mmol) of 2,7-dibromo-N-nonylcabazole and 35 mL of DMF, Lt; 0 > C for 30 minutes. Then, 5,7-bis (tributylstannyl) 2,3-dihydrothieno [3,4- b] [1,4] dioxin (5,7-bis (tributylstannyl) (0.0116 g, 0.01 mol) of tetrakis (triphenyl phosphine) palladium (3.35 g, 4.65 mmol) was added thereto, Stir for 26 h. The resulting mixture was cooled and then DMF was removed using a rotary evaporator. A solid residue was obtained, which was purified with ethanol to obtain 1.39 g of a conductive polymer (SCPB) represented by the following formula. The yield was 69%.

[Formula 2]

¹ H-NMR (400 MHz, CDCl ₃ ):? 8.31-7.28 (m, 6H), 4.40-4.02 (m, 4H), 2.82

^{13 C NMR (100 MHz, CDCl} 3): δ 130.8, 128.8, 128.6, 128.3, 126.2, 126.1, 120.3, 117.9, 106.3, 66.1, 64.7, 60.4, 43.0, 38.8, 31.9, 30.4, 29.5, 29.4, 29.3, 29.0, 27.3, 23.8, 23.0, 22.6, 14.2, 14.04, 14.00, 11.0 ppm

IR (KBr) 2925, 2854, 1739, 1456, 1429, 1361, 1332, 1089 cm ^-1 .

The amount of the element obtained from the above result: C, 74.53; H, 7.31; N, 3.52 (calculated amount for C ₂₇ H ₂₉ NO ₂ S: C, 74.77; H, 7.08; N, 3.23)

Weight average molecular weight (Mw): 1.3 X 10 ⁵

Number average molecular weight (Mn): 6.6 X 10 ⁴

Example 1

A screen printing electrode having a structure as shown in FIGS. 5A to 5C was fabricated using the working electrode 500 capable of performing performance evaluation by fabricating eight ion sensors at one time. The quadrangular portion above the working electrode 500 is connected to the potentiometer and the ion selective membrane solution 11c (see FIG. 5D) is dropped on the circular portion 11 below And dried. More specifically, the working electrode 500 is fabricated as shown in FIG. 5D. Referring to FIG. 5C, a silver layer 10 is formed on the alumina substrate 40 by a screen printing method, heat-treated at 120 ° C for 15 minutes, The insulator layers 20 and 30 were formed on the electrodes by a screen printing method and heat-treated at 120 DEG C for 15 minutes. Then, the exposed silver electrode was immersed in a 0.1 M ferric chloride (FeCl ₃ ) solution for about 30 minutes to form a refractory silver chloride layer 11 b (Step 1). Next, according to the composition shown in the following Table 1, a composition comprising valinomycin as a potassium carrier, SCPA prepared in Synthesis Example 1 as a conductive polymer, and silicone rubber as a polymer matrix was dissolved in 0.4 mL of tetrahydrofuran The solution 11c was drop-coated on a sensing area (0.25 mm ² ) 11 of a flat electrode using a pneumatic dispenser (Step 2) after diluting it in a tetrahydrofuran (THF) Dried at room temperature overnight (Step 3) to prepare a potassium ion selective membrane electrode.

Example 2

A potassium ion selective membrane electrode was prepared in the same manner as in Example 1, except that SCPB prepared in Synthesis Example 2 was used as a conductive polymer.

Example 3

Except that 4-tetrabutylcalix [4] arene-tetraacetic acid tetraethyl ester (4-tert-butylcalix [4] arene-tetraacetic acid tetraethyl ester (Calix [4] arene) was used as a sodium ion carrier. The sodium ion selective membrane electrode was prepared in the same manner as in Example 1.

Example 4

A sodium ion selective membrane electrode was prepared in the same manner as in Example 3 except that SCPB prepared in Synthesis Example 2 was used as a conductive polymer.

Example 5

A hydrogen ion selective membrane electrode was prepared in the same manner as in Example 1, except that tridodecylamine (TDDA) was used as a hydrogen ion carrier.

Example 6

A hydrogen ion selective membrane electrode was prepared in the same manner as in Example 5, except that SCPB prepared in Synthesis Example 2 was used as a conductive polymer.

Comparative Example 1

(PVC) and bis (2-ethylhexyl) sebacate (DOS) were used as the polymer matrix in Example 1 and conductive polymer , A potassium ion selective membrane electrode was prepared.

Comparative Example 2

A potassium ion selective membrane electrode was prepared in the same manner as in Example 1, except that the conductive polymer was not included in Example 1.

Comparative Example 3

Poly (3,4-ethylenedioxythiophene) -block-poly (ethylene glycol), lauryl terminated, and poly (3,4-ethylenedioxythiophene) Potassium perchlorate (CCPA) as a dopant) was used in place of potassium perchlorate to prepare a potassium ion selective membrane electrode.

Comparative Example 4

Poly (3,4-ethylenedioxythiophene) -block-poly (ethylene glycol), which is commercially available as a conductive polymer in Example 1, (CCPB), which is dispersed in a concentration of 1 wt%, was used in place of the potassium ion selective membrane electrode.

Comparative Example 5

Poly (3,4-ethylenedioxythiophene) -block-poly (ethylene glycol), a poly (3,4-ethylenedioxythiophene) -block-poly (ethylene glycol) commercialized as a conductive polymer in Example 1, (CCPC), which was dispersed in a concentration of 1 wt%, was used in place of the potassium ion selective membrane electrode.

Comparative Example 6

4-tetrabutylcalix [4] arene-tetraacetic acid tetraethyl ester (Calix [4] arene) was used as a sodium ion carrier in Comparative Example 1 Was prepared in the same manner as in Comparative Example 1 to prepare a sodium ion selective membrane electrode.

Comparative Example 7

Tetrabutylcalix [4] arene-tetraacetic acid tetraethyl ester (Calix [4] arene) was used as a sodium ion carrier in Comparative Example 2 Was prepared in the same manner as in Comparative Example 2 to prepare a sodium ion selective membrane electrode.

Comparative Example 8

In Comparative Example 1, poly (vinylchloride) (PVC) and 2-nitrophenyl octyl ether (NPOE) were used as a polymer matrix, and tridodecylamine except that tridodecylamine (TDDA) was used instead of tridodecylamine (TDDA).

Comparative Example 9

A hydrogen ion selective membrane electrode was prepared in the same manner as in Comparative Example 2, except that tridodecylamine (TDDA) was used as a hydrogen ion carrier in Comparative Example 2.

PVC ¹⁾ DOS ²⁾ NPOE ³⁾ RTV-
3140 Balnommaisin Calix [4] -
Areen TDDA ⁴⁾ KTFPB ⁵⁾ SCPA SCPB CCPA CCPB CCPC Comparative Example 1
(K-PVC) 33 66 - - 2 - - 0.64 - - - - - Comparative Example 2
(K-SR) - - - 99 2 - - 0.64 - - - - - Example 1
(K-SCPA) - - - 99 2 - - 0.64 2 - - - - Example 2
(K-SCPB) - - - 99 2 - - 0.64 - 2 - - - Comparative Example 3
(K-CCPA) - - - 99 2 - - 0.64 - - 1.09 - - Comparative Example 4
(K-CCPB) - - - 99 2 - - 0.64 - - - 1.18
- Comparative Example 5
(K-CCPC) - - - 99 2 - - 0.64 - - - - 1.11 Comparative Example 6
(Na-PVC) 33 66 - - - 2 - 0.73 - - - - - Comparative Example 7
(Na-SR) - - - 99 - 2 - 0.73 - - - - - Example 3
(Na-SCPA) - - - 99 - 2 - 0.73 2 - - - - Example 4
(Na-SCPB) - - - 99 - 2 - 0.73 - 2 - - - Comparative Example 8
(H-PVC) 33 - 66 - - - 3 2.07 - - - - - Comparative Example 9
(H-SR) - - - 99 - - 3 2.07 - - - - - Example 5
(H-SCPA) - - - 99 - - 3 2.07 2 - - - - Example 6
(H-SCPB) - - - 99 - - 3 2.07 - 2 - - - ¹⁾ Poly (vinylchloride)
²⁾ bis (2-ethylhexyl) sebacate (bis (2-ethylhexyl) sebacate)
³⁾ 2-nitrophenyl octyl ether
⁴⁾ Tridodecylamine
⁵⁾ Potassium tetrakis [3,5-bis- (trifluoromethyl) phenyl] borate (potassium tetrakis [3,5-bis- (trifluoromethyl) phenyl] borate

※ The unit of each content in the above table is mg.

evaluation

(Potentiometric titration)

In order to evaluate the performance of the sensor, as shown in FIG. 6, in a device equipped with a high-impedance input 16-channel analog-digital converter 200 and a magnetic stirrer 300, a screen printing electrode 500 The potential difference was measured using a double-junction reference electrode (Orion 90-02) (310) of Orion as a reference electrode. To store the potential difference between the ion selective membrane electrode and the reference electrode, a high impedance input 16 channel analog-to-digital converter 200 was connected to the IBM compatible computer 100 to store the measured potential difference in the IBM compatible computer 100. Tris (hydroxymethyl) aminomethane (Tris) -H ₂ SO ₄ , pH 7.4) solution of 0.05 M was used as the electrolyte solution.

1. Signal evaluation according to ion concentration

Potentiometric titration was performed on the test solutions containing K ⁺ ions in the concentration range of 10 ^-6 to 10 ^-1 M for the electrodes prepared in Examples 1 and 2 and Comparative Examples 2, 3, 4 and 5. The results are shown in Fig. A severe noise level was confirmed in the electrode when the polymer matrix contained silicon rubber and no conductive polymer (Comparative Example 2) was used. This was the same in the case of Comparative Example 4 as well. On the other hand, in the electrodes of Examples 1 and 2 including the conductive polymer (SCPA and SCPB) of the present invention, the noise level was very small and the stable response signal was shown and the response time was also short. This shows excellent signal sensitivities even when compared with Comparative Example 3 in which the conventional conductive polymer (CCPA) is contained. On the other hand, in Comparative Example 5, the signal tends to decrease as the K ⁺ ion concentration increases.

2. Evaluation of signal stability and response time

In order to evaluate the stability of the response signal and the response time in the electrode prepared from the electrode composition of the present invention, the test solutions containing the same concentration of ions were tested in Examples 1 to 6 and Comparative Examples 1, 2, 6, 7, 8, 9 signal was obtained. The results are shown in Figure 2, along with data on the noise level and stabilization time for each signal. When PVC was used as a polymer matrix, the initial increased signal tended to decrease gradually (K ⁺ and N ⁺ ions) or the signal decreased after the test solution administration (H ⁺ ion) The response signal could not be obtained. Further, when the silicone rubber not containing the conductive polymer of the present invention was used, the noise was excessively high. On the other hand, in the electrode including SCPA and SCPB, the noise level was remarkably decreased in all the ions, and stable signals were obtained and it was confirmed that the stabilization was fast.

3. Impedance measurement

To evaluate the membrane resistance of the electrodes prepared in Examples 1 to 6 and Comparative Examples 2, 7 and 9, each electrode was immersed in 0.1 M KCl, NaCl and HCl solution for 4 hours, and then the potentiostat / galvanostat (CH Instruments 760D ) Was used to obtain a Nyquist plot. A platinum plate was used as an auxiliary electrode, and a Vycor reference electrode including an Ag / AgCl electrode was used as an external electrode. The amplitude of the sinusoidal voltage was 0.1 V, and the period was 100,000 to 0.01 Hz. Membrane resistance was calculated using the Nyquist plot. The measurement results are shown in Fig. (Comparative Examples 2, 7, and 9), a very high electrical resistance of 1039 MΩ, 1490 MΩ, and 1350 MΩ for K ⁺ , Na ^+, and H ⁺ , respectively, when the silicone rubber without the conductive polymer of the present invention was used as a polymer matrix Value was obtained. However, in the case where the conductive polymer of the present invention is included, it is confirmed that the circle radius of the Nyquist plot is greatly reduced and the electrical resistance is significantly reduced. It can be seen that the membrane resistance can be remarkably lowered by adding the conductive polymer SCPA or SCPB of the present invention to a polymer matrix having a large electrical resistance such as silicone rubber. On the other hand, the resistance value of the conductive polymer SCPB was 156 MΩ, 267 MΩ and 171 MΩ for K ⁺ , Na ⁺ and H ⁺ , respectively, which were better than those of SCPA of 375 MΩ, 495 MΩ and 335 MΩ. This is presumably due to the higher electrical conductivity of SCPB (3.08 × 10 ^-3 S / cm, in the case of SCPA, 4.25 × 10 ^-3 S / cm). Therefore, it can be seen that conductive polymer SCPB is more useful than SCPA in manufacturing ion selective membrane electrodes.

4. Lifetime characteristics

The presence of various surfactants (cations, anions, neutral molecules) in the test solution affects the signal slope and detection limits and also causes a phenomenon in which ion selectivity is reduced or reversed. Therefore, in order to evaluate the lifetime characteristics of the sensor, the signal slopes in the test solutions containing various surfactants were measured for the electrodes of Examples 1 to 6 and Comparative Examples 1, 2, 6, 7, 8 and 9. Background Electrolyte hexadecyltrimethylammonium bromide (CTAB) was added at a concentration of 10 ^-4 M in 0.05 M tris (hydroxymethyl) aminomethane, (Tris) -H ₂ SO ₄ , pH 7.4) A test solution containing Triton X-100 and sodium dodecylsulfate (SDS) was used. The results are shown in Figure 4. First, , 6, 8) showed significant signal slope changes at the beginning of the test (within 0 to 3 hours) and this was also true for the K-SR and Na-SR membranes (Comparative Examples 2 and 7), whereas SCPA and SCPB It was confirmed that the effect of the film prepared in the example of the present invention added was much reduced.

In the case of Triton X-100, the change of the signal slope was remarkable in the PVC and SR single use films (Comparative Examples 1, 2, 6, 7, 8 and 9) Respectively.

On the other hand, in the case of SDS, a random change in the signal slope was observed in the K-SR (Comparative Example 2), and it was found that the membrane produced in the embodiment of the present invention had some influence (H-SCPA, In general, the change in signal slope with time was stable, and the superannuation phenomenon that the response slope was increased in H-SR (Comparative Example 9) and H-SCPA (Example 5) was observed, but H-SCPB Example 6) showed additional properties that could improve the disadvantages of H-SR (Comparative Example 9) by showing nernstian response.

From the above results, it can be seen that the membrane containing the conductive polymer SCPA or SCPB of the present invention has excellent lifetime characteristics as compared with the PVC membrane and the SR single membrane.

10: silver layer
11: Ion-
11a: ion-selective membrane 11b: silver chloride 11c: ion-selective membrane mixture
12: Measuring device connection
20, 30: insulating layer
40: Alumina substrate
100: personal computer
200: pH / Ion Meter
300: Magnetic stirrer
310: Refrernce electrode
500: working electrode

Claims (13)

A composition for preparing a solid ion selective membrane electrode, which comprises a polymer matrix, an ionophore and a conductive polymer represented by the following formula 1 or 2:
[Formula 1]

[Formula 2]

The method of claim 1,
The polymer matrix may be selected from the group consisting of poly (vinyl chloride), silicone rubber, polyurethane, poly (vinyl chloride) carboxylate, polyvinyl chloride characterized in that it is selected from the group consisting of chloride, amide, poly (methylacrylate), poly (ethylene oxide), xerogel and combinations thereof. Composition. The method of claim 1,
The ionophore is a potassium ion (K ^+), sodium ion (Na ^+), hydrogen ions (H ^+), lithium ions (Li ^+), rubidium ions (Rb ^+), cesium ion (Cs ^+), magnesium ion (Mg ^2+), calcium ion (Ca ^2+), strontium ion (Sr ^2+), barium ion (Ba ^2+), copper ion (Cu ^2+), ion (Ag ^+), zinc ion (Zn ²⁺⁾ , Cadmium ion (Cd ²⁺ ), mercury ion (Hg ²⁺ ), thallium ion (Tl ⁺ ), lead ion (Pb ²⁺ ), uranium oxide ion (UO ₂ ²⁺ ), samarium ion (Sm ³⁺ ) ammonium ion (NH ₄ ^+), carbonate ions (CO ₃ ^2-), thiocyanate ion (SCN ^-), nitrite ion (NO ₂ ^-), hydroxide ions (OH ^-), phosphine ion (HPO ₄ ^2-) , Abu hydrogen sulfide ions (HSO ₃ ^-), sulfate ion (SO ₄ ^2-), chloride ion (Cl ^-), perchlorate ion (ClO ₄ ^-), iodine Chemistry ion (I ^-), three iodide ion (I ₃ ^- ) and fluorine ions (F ^-) ions selected solid phase which is characterized in that the carrier of ion selected from the group consisting of Film composition for electrode production. The method of claim 1,
Wherein the conductive polymer is contained in an amount of 0.1 to 4% by weight based on the total weight of the composition. The method of claim 1,
Wherein the composition comprises a solvent selected from the group consisting of CHCl ₃ , CH ₂ Cl ₂ , and tetrahydrofuran (THF). The method of claim 1,
Wherein the amount of the solid component in the composition is in the range of 10 to 40% by weight. The method of claim 1,
The composition may include potassium tetrakis (4-chlorophenyl) borate (KT p ClPB), potassium tetrakis [3,5-bis (trifluoromethyl) phenyl] 3,5-bis (trifluoromethyl) phenyl] borate (KTFPB), sodium tetrakis [3,5-bis (trifluoromethyl) phenyl] borate (NaTFPB)), sodium tetrakis (4-fluorophenyl) borate dihydrate (NaT p FPB), sodium tetraphenylborate (NaTPB), tetrabutylammonium Tetrabutylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium tetraphenylborate (TBATPB), tridodecylmethylammonium chloride (TDMACl), tridodecylmethylammonium nitrate, tetraoctylammonium bromide, (Tetraheptylammonium tetraphenylborate (THATPB)) and tetraphenylphosphonium tetraphenylborate (ETH500), tetraethylammonium tetrakis (4-chlorophenyl) borate (Tetradodecylammonium tetrakis TPPTPB). ≪ / RTI > The composition for preparing a solid ion selective membrane electrode according to any one of the preceding claims, further comprising at least one additive selected from the group consisting of: A silver / silver chloride electrode printed on a substrate and a working electrode comprising an ion selective film on which the composition for preparing a solid phase ion selective membrane electrode according to any one of claims 1 to 7 is drop-coated on the silver / silver chloride electrode The ion sensor features. 9. The method of claim 8,
Wherein the ion selective membrane comprises a conductive polymer expressed by the following formula 1 or 2 in an amount of 0.1 to 4 wt% based on the total weight of the membrane:
[Formula 1]

[Formula 2]

9. The method of claim 8,
Wherein the ion selective membrane comprises a silicone rubber as a polymer matrix. 9. The method of claim 8,
Wherein the ion-selective membrane has a thickness of 100 to 300 mu m. 9. The method of claim 8,
The ion sensor, potassium ion (K ^+), sodium ion (Na ^+), hydrogen ions (H ^+), lithium ions (Li ^+), rubidium ions (Rb ^+), cesium ion (Cs ^+), magnesium ion (Mg ^2+), calcium ion (Ca ^2+), strontium ion (Sr ^2+), barium ion (Ba ^2+), copper ion (Cu ^2+), ion (Ag ^+), zinc ion (Zn ²⁺⁾ , Cadmium ion (Cd ²⁺ ), mercury ion (Hg ²⁺ ), thallium ion (Tl ⁺ ), lead ion (Pb ²⁺ ), uranium oxide ion (UO ₂ ²⁺ ), samarium ion (Sm ³⁺ ) ammonium ion (NH ₄ ^+), carbonate ions (CO ₃ ^2-), thiocyanate ion (SCN ^-), nitrite ion (NO ₂ ^-), hydroxide ions (OH ^-), phosphine ion (HPO ₄ ^2-) , Abu hydrogen sulfide ions (HSO ₃ ^-), sulfate ion (SO ₄ ^2-), chloride ion (Cl ^-), perchlorate ion (ClO ₄ ^-), iodine Chemistry ion (I ^-), three iodide ion (I ₃ ^- ) and fluorine ions (F ^-) ions, characterized in that indicating a selectivity for ions selected from the group consisting of Standing. 9. The method of claim 8,
Wherein the working electrode is a disk electrode, a screen printing electrode, or a needle.

Images