KR20180082371A - Nanopipette having an membrane comprising saturated ionophore - Google Patents

Abstract

The present invention discloses a nano pipette having a membrane comprising a saturated ion sensing material, a method for manufacturing the same, and an ion measuring device including the same. The ion selective nano pipette can perform selective ion measurement by generating an electric current signal through ion exchange with the same ion as the ion saturating the ion sensing material in a sample.

Description

≪ Desc / Clms Page number 1 > NANOPIPETTE HAVING AN MEMBRANE COMPRISING SATURATED IONOPHORE < RTI ID = 0.0 >

The present invention relates to a nanopipette having a membrane comprising a saturated ion-sensitive material, and more particularly to a nanopipette comprising a nanopipette with an ion-selective membrane, wherein the ion-selective membrane comprises a saturated ion- About nano-pipettes

Ion Selective Electrode (ISE) is a type of membrane electrode that has a membrane that selectively responds to specific ions in a solution. The ion concentration (activity) can be determined by measuring the potential generated at the interface between the membrane and the solution . The ion-selective electrode may be referred to as a potentiometric ion sensor. The ion-selective electrode comprises an ion selective membrane, which is the most important part of the ion selective electrode, which is a membrane that generates voltage by sensing the specific ion directly contacting the analytical sample .

Ion selective electrodes can measure the concentration of specific ions present in a sample solution and thus can be used for various applications such as food chemistry, fermentation process, environmental analysis, hemodialysis, continuous automatic measurement of hematoma electrolyte, extracorporeal blood It is used in many fields such as clinical chemistry. On the other hand, the local ion concentration can be measured using a nanopipette-controlled Scanning Ion-Conductance Microscope (SICM), which can also be controlled on a nanoscale scale, current, that is, the total ion current, it is not easy to identify a specific ion distribution.

Although the conventional ISE method can measure ions to be detected, the size of the pipette tip part is very large in millimeters (mm), and since the concentration range of the measurable ions is also large, only a high concentration measurement is possible there was. However, ion filter electrodes have recently been developed to solve these size problems and to detect ions at low concentrations.

The ion filter electrode is a method of making plasticized PVC into a film inside the pipette, which can reduce the diameter of the pipette tip to several hundred nanometers. However, the ion filter electrode can not reuse the ion sensing material existing in the PVC film after use, and there is a problem that it is not possible to measure a desired kind of ions in an aqueous solution containing three or more ions.

In order to solve the problem of the conventional ion filter electrode, the present inventors have made it possible to selectively detect one or more ions by applying an ion selective membrane having a saturated ion-sensitive material inside the nano-pipette.

According to a first aspect,

Disclosed is an ion-selective nanopipette characterized in that it comprises an ion selective membrane containing an ionophore, a polymeric matrix and a plasticizer, the ionic sensing material being saturated.

The ion-selective nanopipette according to the first embodiment of the present invention may include a middle membrane collector positioned at the center in the longitudinal direction of the nanopipette.

The ion-selective nanopipette according to the second embodiment of the present invention may comprise a conical shank membrane collector located in the nano-pipette bottom conical shank.

According to a second aspect,

(A) preparing a film forming solution containing an ionophore, a polymeric matrix and a plasticizer;

(B) injecting a film forming solution into a nano pipette to form an ion selective film; And

And (C) saturating the ion sensing material in the membrane.

A method for preparing an ion-selective nanopipette according to the first embodiment of the present invention comprises:

(a) preparing a film forming solution containing an ion sensing material, a polymeric support, and a plasticizer;

(b) injecting deionized water into the interior of the nanopipette from the top of the nanopipette;

(c) injecting the film forming solution onto the deionized water to form an ion selective film; And

(d) injecting an electrolyte onto the ion selective membrane.

(E) injecting a solution having the same concentration as that of the electrolyte injected in step (d) into the tip tip of the nano-pipette.

The ion-selective nanopipette fabricated according to this embodiment may include an ion-selective middle membrane collector positioned in the longitudinal direction of the nanopipette.

A method for preparing an ion-selective nanopipette according to a second embodiment of the present invention comprises:

(a) preparing a film forming solution containing an ion sensing material, a polymeric support, and a plasticizer;

(b) injecting the film forming solution to a tip end of a nano-pipette to form an ion selective film; And

(c) injecting an electrolyte into the interior of the nanopipette from the top of the nanopipette.

The method for preparing an ion-selective nanopipette according to the above embodiment may further comprise the step of (d) placing the lower tip end of the nanopipette in a solution having the same concentration as that of the electrolyte injected in step (c).

The ion-selective nanopipette fabricated according to this embodiment may comprise a conical shank membrane collector located in the nano-pipette bottom conical shank.

According to a third aspect,

A nano-pipette comprising a membrane containing an ionophore, a polymeric matrix and a plasticizer, an inner electrode in contact with the inner solution, a counter electrode in contact with the outer solution, And a measuring circuit for connecting the counter electrode to the counter electrode, wherein the ion sensing material is saturated. The measurement circuit may include a current-to-voltage converter, an amplifier for transferring a voltage difference between the internal electrode and the counter electrode, and a detector for detecting a signal.

A nanopipette comprising a membrane containing a saturated ion sensing material according to the present invention is capable of selectively detecting a desired ion. The nanopipette comprising a membrane containing a saturated ion-sensitive material according to the present invention can selectively measure target ions even in a sample solution in which a plurality of ions are mixed. In addition, a nanopipette containing a membrane containing a saturated ion-sensitive material according to the present invention can be reused.

Figure 1 shows an example of a cation-ion sensing material complex according to the present invention.
Figure 2 shows the ion exchange principle of a middle membrane collector positioned centrally in accordance with the present invention.
Figure 3 shows the ion exchange principle of a conical shank membrane collector located in a conical shank according to the present invention.
FIG. 4 illustrates a method for preparing an ion-selective nanopipette comprising a middle membrane according to the present invention.
Figure 5 illustrates a method of making an ion-selective nanopipette comprising a conical shank membrane in accordance with the present invention.
6 shows an example of an ion selective electrode according to the present invention.
7 shows SEM measurement results of a nanopipette manufactured according to the present invention.
FIG. 8 shows the ion selectivity measurement results of an ion membrane positioned in the middle according to Experimental Example 1 of the present invention.
9 shows the result of ion selective measurement of the ionic membrane located in the conical shank according to Experimental Example 1 of the present invention.
10 shows the result of checking the reproducibility of the potassium-selective membrane placed on the conical shank according to Experimental Example 2 of the present invention.
Fig. 11 shows the reproducibility confirmation result of the sodium-selective membrane located in the conical shank located in Experimental Example 2 of the present invention.

Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Various scientific dictionaries, including the terms contained herein, are well known and available in the art. Although any methods and materials similar or equivalent to those described herein are found to be used in the practice or testing of the present application, some methods and materials have been described. Should not be construed as limiting the invention to the particular methodology, protocols and reagents, as they may be used in various ways in accordance with the context in which those skilled in the art use them.

As used herein, the singular forms include plural objects unless the context clearly dictates otherwise. As used herein, unless otherwise stated, "or" means "and / or ". Furthermore, it is to be understood that other forms, such as " having ", "consisting ", and" consisting "

The numerical range includes numerical values defined in the above range. All numerical limitations of all the maximum numerical values given throughout this specification include all lower numerical limitations as the lower numerical limitations are explicitly stated. All the minimum numerical limitations given throughout this specification include all higher numerical limitations as the higher numerical limitations are explicitly stated. All numerical limitations given throughout this specification will include any better numerical range within a broader numerical range, as narrower numerical limitations are explicitly stated.

The subject matter provided herein should not be construed as limiting the following embodiments in various aspects or as a reference throughout the specification.

According to a first aspect, the present invention is characterized in that it comprises an ion-selective membrane containing an ionophore, a polymeric matrix and a plasticizer, said ion-sensing material being saturated Lt; RTI ID = 0.0 > ion-selective < / RTI >

As used herein, the term "ion " refers to an atom or a specific state of a molecule, which means an atom or molecule that loses electrons or charges electrons. Positively charged ions are called cations and negatively charged ions are called anions. The ions are potassium ions (K ^+), sodium ion (Na ^+), calcium ions (Ca ^{2 +),} manganese ion (Mn ^{+ 2),} Copper ions (Cu ^2+), cerium ions (Ce ^{+ 2)} and hydrogen Ion (H ⁺ ), but the present invention is not limited thereto.

The term "nano-pipette" as used herein is intended to include a nano-sized conical tip opening, for example a hollow wedge-shaped opening with a tip opening of 0.05 nm to 500 nm, 50 nm to 200 nm, , Inert, non-biological structure. The hollow structure can be, for example, glass or quartz, and can hold therein fluid passing through the tip opening. The interior of the nanopipette can be selected or modified to minimize nonspecific binding of the analyte. The interior of the nanopipette is typically in the form of an extended cone having a uniform wall thickness of a single layer of quartz or other biologically inert material and may be sized to allow insertion of the electrode in contact with the solution in the nanopipette. The nanopipettes used herein generally have one hole, but a nanopipette having a plurality of concentric holes can be produced by pulling the double-hole capillary. The outer diameter may generally be less than about 1 [mu] m in the tip region.

The term "membrane" or "ion selective membrane ", as used interchangeably herein, refers to a membrane that is included in an ion selective electrode (ISE) By way of example, the membrane can generally consist of an ionophore, a polymeric matrix and a plasticizer.

As used herein, the term "ion sensing material" means a material capable of causing a covalent bond, coordination bond or ion exchange reaction with a specific ion. The ion sensing material may be selected from the group consisting of quaternary ammonium salts, valinomycin, valenomycin derivatives, monensin, nonactin, novotine derivatives, tertiary amines, metal porphyrin, metal phthalocyanine, trifluoroacetophenone, trifluoroacetophenone derivatives, crown ether, dibenzo-18-crown- 6), organophosphorus ion sensing material, organosilicate ion sensing material, ETH1778, ETH1062, ETH1001, ETH129, ETH149, ETH1644, ETH1117, ETH5214, ETH227 and ETH157. It is not.

An example of a saturated ion-sensitive material, that is, a cation-ion-sensing material composite according to the present invention is shown in FIG. 1, and the ion-exchange membrane of an ion-selective membrane including the cation- Respectively.

The term "saturated ion sensing material" as used herein means that the ion sensing material in the membrane combines with the cation to form a "cation-ion sensing material complex ".

As shown in FIG. 2, the ion sensing material reacts with the ions detected by the ion sensing material, and the ion sensing material that has already been saturated transmits the corresponding ions through the ion exchange to generate the current, thereby enabling the measurement of the selective ion. That is, in the case of an ion such as a ion which is saturated with the ion sensing substance in the film and forms a complex, it passes through the membrane through ion exchange. Otherwise, the ion exchange does not occur and is reflected. Therefore, the same ion as the ion that saturates the ion sensing material is activated by ion exchange, and a signal is generated through the membrane. When another ion is applied, no signal is detected.

Therefore, in the case of a nanopipette having a membrane containing a saturated ion-sensitive material according to the present invention, the kind of ions used for saturating the ion-sensing material, that is, The kind of ions can be controlled.

The term "polymeric support " as used herein means a structure of a film that appropriately disperses and maintains the properties of the other components of the mixed solution constituting the membrane in a well-maintained state. The polymer scaffold may be selected from the group consisting of a silicone rubber, a copolymer of poly (bisphenol-A carbonate) and poly (dimethylsilyoxine), poly (methyl methacrylate) (PMMA), polyurethane (PUR or PU), polyetherimide PEI) and poly (vinyl chloride) (PVC), but are not limited thereto.

The term "plasticizer " as used herein means a non-volatile organic solvent used in a high proportion to reduce the rigidity of the polymeric scaffold. The plasticizer may be selected from o-nitrophenyl octyl ether, bis (2-ethylhexyl) sebacate, dioctyl phthalate, bis (1-butylpentyl) adipate, dioctylphenyl phosphate, tris Nitro phenyl phenyl phosphate, and dibutyl phthalate, but is not limited thereto.

According to the present invention, the ion-selective membrane may further include an anion repeller.

As used herein, the term " anion repeller "serves to reflect anions and reflects the anions so that the cations are more easily accessible around the membrane. The anion repeller may be selected from the group consisting of triphenylboron, tris (pentafluoropheneyl) boron, tris (3,5-di (trifluoromethyl) phenyl) boron (pentafluorophenyl) borate salt), tetrakis (pentafluorophenyl) borate salt, and the like can be selected from the group consisting of trifluoromethyl phenyl boron, tetraphenylborate salt and tetrakis It is not.

According to a first embodiment of the present invention, the ion-selective nanopipette may comprise a middle membrane collector positioned in the longitudinal direction of the nanopipette.

According to a second embodiment of the present invention, the ion-selective nanopipette may comprise a conical shank membrane collector located in the nano-pipette bottom conical shank. The ion exchange principle of the ion selective membrane located in the conical shank is shown in Fig.

Specifically, the ion exchange of the ion selective membrane located in the lower conical shank of the nano-pipette is also the same as the ion exchange of an ion selective membrane located at the center in the longitudinal direction of the nano-pipette. However, since the ion selective membrane located at the conical shank is formed at the tip of the nano-pipette, ion exchange occurs at the same time the sample solution is added, so that the ion exchange activity may occur more rapidly than the ion- Thus, noise can be reduced and a more stable signal can be obtained.

According to a second aspect, the present invention provides a method of making an ion-selective nanopipette. The method comprises: (A) preparing a film forming solution containing an ionophore, a polymeric matrix and a plasticizer; (B) injecting a film forming solution into a nano pipette to form an ion selective film; And (C) saturating the ion sensing material in the ion selective membrane.

The film forming solution according to the present invention contains an ion sensing material, a polymer scaffold and a plasticizer, and may further contain an anion repeller. Specifically, the film-forming solution according to the present invention comprises bis (benzo-15-crown-5) and / or bis (12-crown-4) as an ion sensing substance, PCV as a polymeric support, o-nitrophenyl octyl ether (o-nitrophenyloctylether) and tetraphenylborate (anion repeller) in a ratio of 5: 32: 62: 1. The film forming solution may be dissolved in tetrahydrofuran. The chemical structures of the ion sensing materials bis (benzo-15-crown-5) and bis (12-crown-4) are shown in chemical structure 1 (a) and chemical structure 2 (b), respectively.

[Chemical Structure 1]

Referring to the above chemical structure, the ring part of bis (benzo-15-crown-5) and bis (12-crown-4) Thus, potassium ion and sodium ion can bind to the negative charge portion. The size of the potassium ion is about 152 pm and the size of the sodium ion is about 116 pm. Therefore, it can bind to bis (benzo-15-crown-5) and bis (12-crown-4) according to the size.

The method for preparing the ion-selective nanopipette according to the first embodiment of the present invention comprises the steps of: (a) preparing a film forming solution containing an ion sensing material, a polymer scaffold and a plasticizer; (b) injecting deionized water into the interior of the nanopipette from the top of the nanopipette; (c) injecting the film forming solution onto the deionized water to form an ion selective film; And (d) injecting an electrolyte onto the ion selective membrane. (E) injecting a solution having the same concentration as that of the electrolyte injected in step (d) into the tip tip of the nano-pipette. The ion-selective nanopipette fabricated according to this embodiment may include a middle membrane in the longitudinal direction of the nanopipette. A method for preparing an ion-selective nanopipette according to the above embodiment is shown in FIG.

Referring to FIG. 4, first, deionized water is injected from the upper portion of the nanopipette to the lower tip portion of the nano-pipette. A film forming solution is injected onto the injected deionized water and dried to form an ion selective film. When an electrolyte is injected into the nanopipette to saturate the ion sensing material in the ion selective membrane and a solution having the same concentration as that of the electrolyte is injected into the tip tip of the nipple, the ion selective membrane positioned between the two electrolytes Can be saturated. The ion sensing material is saturated because ions (e.g., K + and / or Na +) present in the electrolyte form a complex while binding with the ion sensing material in the ion selective membrane. .

The method for preparing an ion-selective nanopipette according to the second embodiment of the present invention comprises the steps of: (a) preparing a film forming solution containing an ion sensing material, a polymer scaffold and a plasticizer; (b) injecting the film forming solution to a tip end of a nano-pipette to form an ion selective film; And (c) injecting an electrolyte into the interior of the nanopipette from the top of the nanopipette. The method for preparing an ion-selective nanopipette according to the above embodiment may further comprise the step of (d) placing the lower tip end of the nanopipette in a solution having the same concentration as that of the electrolyte injected in step (c). The ion-selective nanopipette fabricated according to this embodiment may comprise a conical shank membrane located on the nano-pipette bottom conical shank. A method for preparing an ion-selective nanopipette according to this embodiment is shown in FIG.

Referring to FIG. 5, first, a film forming solution is injected into a nanopipe and dried to form an ion selective film. In order to saturate the ion sensing material in the ion selective membrane, an electrolyte is injected into the interior of the nano pipette from the top of the nano pipette, and then the lower tip end of the nano pipette is positioned in the same concentration solution as the electrolyte, The ion selective membrane located between the electrodes can be saturated. The ion selective membrane can be saturated because the ions present in the electrolyte (e.g., K + and / or Na +) form a complex while binding with the ion sensing material in the ion selective membrane.

According to a third aspect, the present invention provides a nanopipette comprising a nanopipette comprising a membrane containing an ionophore, a polymeric matrix and a plasticizer, an inner electrode in contact with the inner solution, a counter electrode and a measuring circuit for connecting the internal electrode and the counter electrode, wherein the ion sensing material is saturated. The measurement circuit may include a current-to-voltage converter, an amplifier for transferring a voltage difference between the internal electrode and the counter electrode, and a detector for detecting a signal. An example of the ion measuring apparatus according to the present invention is shown in Fig.

As used herein, the term "inner solution" refers to a solution comprising an electrolyte to obtain an ionic current signal. The electrolyte is a substance containing a free ion and may be selected from the group consisting of sodium, potassium, calcium, magnesium, chloride, phosphate and bicarbonate, but is not limited thereto. Day or more, but is not limited thereto.

The term "external solution" as used herein refers to a sample solution containing ions to be measured, and may include live cells, plasma, and other body fluids.

As used herein, the term "measuring circuit" measures a specific ion signal with alternating current (AC), the output current follows a change in input voltage, and a small change in current can also be detected.

The nano-pipette including the membrane containing the saturated ion-sensitive material according to the present invention can selectively detect a desired ion according to the type of the ion-sensing material and the type of ions that saturate the ion-sensing material. A nano-pipette comprising a membrane containing a saturated ion-sensitive material according to the present invention is capable of selectively measuring target ions in a sample solution having a plurality of ions. In addition, a nanopipette comprising a membrane containing a saturated ion sensing material according to the present invention can reuse the membrane inside the pipette.

Hereinafter, various embodiments are provided to facilitate understanding of the present invention. The following examples are provided to facilitate understanding of the invention and are not intended to limit the scope of the invention.

Example

Example  1. Manufacturing of nano pipettes

A nanopipette having a diameter of 100 nm was prepared using a borosilicate glass capillary (GD-1, Narishige) equipped with a filament and a CO ₂ laser-based Fuller (Model P-2000, Sutter Instrument). At this time, the used puller setting is as follows:

Heat = 350, Filament = 3, Velocity = 30, Delay = 190, Pull = 0; And

Heat = 330, Filament = 2, Velocity = 27, Delay = 180, Pull = 250.

The nanopipette was observed through a scanning electron microscope (SEM). The results are shown in FIG.

Example  2. Preparation of film-forming solution

(Dozindo CAS 80403-59-4), PVC (Aldrich, CAS 9002-86-2), a plasticizer [o-nitrophenyloctylether (Aldrich, CAS 3244-41-5)], And anion repeller (tetraphenylborate) in a weight ratio of 5: 32: 62: 1. Also, a film forming solution was prepared in the same manner as above except that bis (benzo-15-crown-5) (Dojindo CAS 69271-98-3) was used as the ion sensing material.

Example  3. Preparation of ion-selective electrode

(1) Preparation of a middle membrane collector in the middle

Two nanopipettes prepared in Example 1 were prepared and DI water was injected from the top of the nano-pipette to the tip tip of the nano-pipette using a thin injection needle. Then, the membrane-forming solution prepared in Example 2 was added to the deionized water injected into the nano-pipette, followed by cooling in a dry box for 2 hours to form a membrane. 4 × 10 ^-3 M potassium chloride (KCl) and sodium chloride (NaCl) solutions were respectively injected onto the membrane, and the same solution was injected into the tip tip of the nipipette. This was then stored in a drybox for 2 days to complete a potassium selective membrane saturated with potassium ions and a sodium selective membrane saturated with sodium ions.

(2) Production of Conical shank membrane collector located in conical shank

Two nanopipettes prepared in Example 1 were prepared, and the membrane-forming solution prepared in Example 2 was injected to the tip of the nano-pipette, followed by cooling in a dry box for 2 hours to form a membrane. At this time, the tip portion of the nano-pipette was immersed in deionized water so that the film-forming solution did not harden. Then, 4 × 10 ^-3 M potassium chloride (KCl) or sodium chloride (NaCl) solution was injected into the inside of the nanopipette from the top of the membrane-formed nanopipette, and the tip of the nanopipette was immersed in the same concentration of the solution. This was then stored in a drybox for 2 days to complete a potassium selective membrane saturated with potassium ions and a sodium selective membrane saturated with sodium ions.

Experimental Example  1. According to the invention Saturated  Ion selectivity measurement results of a nanopipe with a membrane containing an ion sensing material

(1) Measurement of ion selectivity of ion membrane located in the middle

6 (a), and an external solution was injected by the method shown in Fig. 6 (b) to obtain a potassium ion-saturated potassium ion-saturated membrane prepared in Example 3 (1) And the signals of potassium and sodium ions for sodium-selective membranes saturated with sodium ions were measured. The results are shown in Fig. 8 (a) and 8 (b) are graphs showing potassium ion and sodium ion, respectively.

As can be seen from FIG. 8 (a), when 0.1 M KCl was added as an external solution to the potassium-selective electrode, the signal increased, but when the 0.1 M NaCl was added, there was almost no change in the signal height. As can be seen from FIG. 8 (b), the signal increased when 0.1 M NaCl was added as an external solution to the sodium-selective electrode, but the signal did not change when 0.1 M KCl was added. The signal to noise ratio (S / N) of the potassium-selective membrane and the sodium-selective membrane was 1.75 and 1.06, respectively.

(2) Measurement of ion selectivity of membranes in conical shanks

The potassium and sodium ion signals for potassium-selective membranes saturated with potassium ions and sodium-selective membranes saturated with sodium ions prepared in Example 3 (2) were measured using the same method as in Experimental Example 1 (1) , And the results are shown in Fig. 9 (a) and 9 (b) are graphs showing potassium ion and sodium ion, respectively.

As can be seen from FIG. 9 (a), the signal increased when 0.1 M KCl was added as an external solution in the potassium-selective membrane, but there was little change in signal when 0.1 M NaCl was added. As can be seen from FIG. 9 (b), the signal increased when 0.1 M NaCl was added as an external solution in the sodium-selective membrane, but the signal did not change significantly when 0.1 M KCl was added. The signal-to-noise ratio (S / N) of the potassium-selective membrane and the sodium-selective membrane was 21.68 and 16.57, respectively.

From the above, it can be seen that the ion selective membrane located in the conical shank increases the S / N ratio by about 15 times as compared with the ion selective membrane located in the middle. In the case of an ion selective membrane located in the middle, an electrolyte exists in the tip portion of the nanopipe. Therefore, it is confirmed that noise is generated by the electrolyte existing in the tip portion of the nanopipette before the ions in the external solution reach the membrane.

Experimental Example  2. Conical Shank  Confirm membrane reproducibility

The saturation process of the ion sensitive material in the potassium-selective membrane and the ion selective membrane prepared in Example 3 (2) was measured for 2 days, 7 days, and 10 days, respectively, using the same method as in Experimental Example 1, And Fig.

As can be seen from FIGS. 10 and 11, it was confirmed that the target ion can be selectively detected even after 2 days, 7 days, and 10 days in the case of the conical shark membrane.

The present invention has been described above with reference to preferred embodiments thereof. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The disclosed embodiments should, therefore, be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (8)

1. An ion-selective nanopipette comprising an ion selective membrane containing an ionophore, a polymeric matrix and a plasticizer,
The ion sensing material is saturated with the sensing ions,
Wherein the ion-selective nanopipette is capable of selective ion measurement by generating a current signal through ion exchange with the same ion as the ion that saturates the ion-sensing material in the sample.
The method according to claim 1,
Wherein the ion selective membrane is centrally located in the longitudinal direction of the nanopipette.
The method according to claim 1,
Wherein the ion-selective membrane is located in the nano-pipette bottom conical shank.
The method according to claim 1,
The ion sensing material may be selected from the group consisting of quaternary ammonium salts, valinomycin, monensin, nonactin, novotine derivatives, tertiary amines, metal porphyrins, Metal phthalocyanine, trifluoroacetophenone, crown ether, dibenzo-18-crown-6, organophosphorus ion sensing materials and organosilicate ions Wherein the ion-selective nanopipette is one or more selected from the group consisting of sensing materials.
The method according to claim 1,
The polymer scaffold may be selected from the group consisting of a silicone rubber, a copolymer of poly (bisphenol-A carbonate) and poly (dimethylsyloxane), poly (methyl methacrylate) (PMMA), polyurethane (PUR or PU), polyetherimide PEI) and poly (vinyl chloride) (PVC). ≪ RTI ID = 0.0 > I. < / RTI >
The method according to claim 1,
The plasticizer may be selected from o-nitrophenyl octyl ether, bis (2-ethylhexyl) sebacate, dioctyl phthalate, bis (1-butylpentyl) adipate, dioctylphenyl phosphate, tris Nitrophenylphenylphosphate, and dibutylphthalate. ≪ Desc / Clms Page number 14 >
The method according to claim 1,
The ion-selective membrane may be formed of a material selected from the group consisting of triphenylboron, tris (pentafluoropheneyl) boron, tris (3,5-di (trifluoromethyl) phenyl) anion repellants selected from the group consisting of tetrakis (trifluoromethyl) phenyl boron, tetraphenylborate salt and tetrakis (pentafluorophenyl) borate salt. ). ≪ / RTI > The ion-selective nanopipette of claim < RTI ID = 0.0 > 1, < / RTI >
The method according to claim 1,
The ion is selected from the group consisting of potassium ion (K +), sodium ion (Na +), calcium ion (Ca 2+), manganese ion (Mn 2+), copper ion (Cu 2+), cerium ion (Ce 2+) Wherein the ion-selective nanopipette is further selected.

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