KR102195506B1 - Detection sensor of heavy metal ion and method thereof - Google Patents

Abstract

The present invention is a sensor that detects specific heavy metal ions (copper, lead) adsorbed on a solid surface based on a change in an electrical signal generated by a change in the contact area between a liquid and a solid surface through the mechanical motion of a liquid droplet, and heavy metal detection using the same It's about how. Liquid ions can be detected with high selectivity and sensitivity by using the surface properties that change due to the specific adsorption of ions on the solid surface. In addition, it has the advantage that it is possible to generate an electric signal by self-generation and that it can be manufactured in a very simple and inexpensive manner.

Description

Heavy metal ion detection sensor and heavy metal ion detection method using the same TECHNICAL FIELD [Detection sensor of heavy metal ion and method thereof]

The present invention relates to a heavy metal ion detection sensor and a heavy metal ion detection method using the same, and more particularly, to a heavy metal ion detection sensor capable of detecting heavy metal ions with high selectivity and sensitivity, and a heavy metal ion detection method using the same.

In many fields such as chemistry, biology, medicine, and environment, it is necessary to quickly and accurately analyze the concentration of various ions contained in a test solution, and chemical sensor materials having selectivity for specific ions are used for this analysis. These materials can be applied to analysis of specific ions by measuring changes in electrical properties such as electricity and resistance to specific ions or optical properties such as color and fluorescence.

Among chemical sensor materials, the development of sensor materials that detect positive and negative ions of heavy metals, organic materials, and strong acids has attracted a lot of attention over the past decades because of their potential applicability in industries, environments, and bio fields. However, detection of positive/anion, organic substances, strong acids, etc. due to changes in the color or fluorescence of the sensor material is limited to some materials because it is difficult to obtain sufficient selectivity or sensitivity due to various characteristics of the analysis target.

In recent years, environmental pollution is increasing day by day, and heavy metal substances among them are known to have a fatal effect on the human body, and interest is also increasing. When heavy metals accumulate in the human body for a long period of time, it is known to cause chronic diseases. In particular, ionized copper (Cu ²⁺ ) is a heavy metal that causes neurodegenerative diseases and requires thorough management. In addition, when lead is absorbed into the human body, it is not excreted again, but is accumulated and negatively affects various physiological and metabolic reactions in the body. Lead poisoning can cause headaches and dizziness, and can pose a fatal risk to the heart, kidneys, and nervous system. In particular, lead poisoning in children may impair learning and behavioral development. In order to recognize the severity of heavy metal contamination and prevent damage, various analysis methods for detecting heavy metal ions are used.

However, conventional ion sensors or chemical sensors require external power or complex deposition and patterning processes such as ion sensing field effect transistors, and very complex and sophisticated measuring devices are required for optical measurement and electrochemical measurement. And, in the case of using the inductively coupled plasma mass spectrometry, equipment of an experimental scale is required.

Korean Patent Registration No. 10-1746517

The present invention provides a heavy metal ion detection sensor capable of self-power generation and detection of heavy metal ions contained in a liquid sample with high selectivity and sensitivity with high selectivity and sensitivity, and a heavy metal ion detection method using the same. It is aimed at.

The present invention to achieve the above object, the first electrode substrate; A second electrode substrate facing the first electrode substrate; And an insulating layer formed on the first electrode substrate, and detecting heavy metal ions by the amount of change in electrical energy generated by a change in the contact surface of water or ionic liquid positioned on the upper surface of the first electrode substrate. It provides a heavy metal ion detection sensor.

In addition, the present invention is a first electrode substrate; A second electrode substrate facing the first electrode substrate; An insulating layer formed on the first electrode substrate; And a self-assembled monomolecular layer formed on the insulating layer, and detects heavy metal ions by an amount of change in electrical energy generated by a change in the contact surface of water or an ionic liquid positioned on the upper surface of the self-assembled monomolecular layer. Provides heavy metal ion detection sensor.

In one embodiment of the present invention, a change in the contact surface of the ionic liquid or water located on the upper surface of the first electrode substrate may occur due to vertical vertical motion of the second electrode substrate.

In another embodiment of the present invention, the ionic liquid may contain heavy metal ions.

In another embodiment of the present invention, the self-assembled monomolecular layer may include a water repellent coating material and an ion adsorption material.

In another embodiment of the present invention, the ion adsorption material may be N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine) or N-[3-(Trimethoxysilyl)propyl]ethylenediamine.

In another embodiment of the present invention, the water repellent coating material is a silane-based material, a fluoropolymer material, a trichlorosilane, a trimethoxysilane, and pentafluorophenylpropyltrichloro. Losilane (Pentafluorophenylpropyltrichlorosilane), (Benzyloxy)alkyltrimethoxysilane ((Benzyloxy)alkyltrimethoxysilane, BSM-22), (Benzyloxy)alkyltrichlorosilane ((Benzyloxy)alkyltrichlorosilane, BTS), Hexamethyldisilazane , HMDS), octadecyltrichlorosilane (OTS), octadecyltrimethoxysilane (OTMS) and divinyltetramethyldisiloxane-bis-(benzocyclobutene) (Divinyltetramethyldisiloxane-bis (benzocyclobutene), BCB ) It may be any one selected from the group consisting of.

In addition, the present invention comprises the steps of preparing a first electrode substrate and a second electrode substrate; Stacking an insulating layer on the first electrode substrate; Forming a self-assembled monolayer on the insulating layer; And adsorbing ions to the upper surface of the self-assembled monolayer by contacting an ionic liquid or water with the upper surface of the self-assembled monolayer. It provides a method of manufacturing a heavy metal ion detecting sensor comprising a.

The self-assembled monolayer may be formed by coating or depositing a water-repellent coating material and an ion adsorption material on the insulating layer.

In addition, the present invention uses the above-described heavy metal ion detection sensor, and after adsorbing the water on the upper surface of the first electrode substrate, the water and the first electrode substrate are vertically moved up and down. Acquiring an amount of electricity generated according to a change in the contact surface of the upper surface; After adsorbing the ionic liquid on the upper surface of the first electrode substrate, the amount of electricity generated according to the change in the contact surface between the ionic liquid and the upper surface of the first electrode substrate by vertical vertical motion of the second electrode substrate is measured. Obtaining; And detecting heavy metal ions by comparing the amount of electricity generated by the water and the amount of electricity generated by the ionic liquid.

The present invention is a sensor that detects specific heavy metal ions (copper, lead) adsorbed on a solid surface based on a change in an electrical signal generated by a change in the contact area between a liquid and a solid surface through the mechanical motion of a liquid droplet, and heavy metal detection using the same It's about how. Liquid ions can be detected with high selectivity and sensitivity by using the surface properties that change due to the specific adsorption of ions on the solid surface. In addition, it has the advantage that it is possible to generate an electric signal by self-generation and that it can be manufactured in a very simple and inexpensive manner.

1 is a diagram illustrating a process of detecting heavy metal ions in a liquid sample using the heavy metal ion detection sensor of the present invention. Figure 1 (a) is a diagram showing the measurement of a reference signal through the mechanical movement of the ion detection sensor in the vertical direction, Figure 1 (b) is the surface exposure of the liquid sample containing the target ions and self-assembled monomolecular layer It is a diagram showing chemical adsorption, and FIG. 1C is a diagram showing measuring a detection signal through vertical motion of an ion detection sensor after chemical adsorption. At this time, the state of a self-assembled monolayer (SAM) is shown on the right side of each diagram. The right side of FIG. 1(a) shows the initial state of the self-assembled monolayer, and the right side of FIG. 1(b) shows the combination of copper ions with the functional groups of the ion-adsorbing material, and FIG. The right side of (c) shows the final state of the ion adsorbed SAM.
2 is a diagram showing a state in which target ions of a liquid sample are chemically adsorbed in a self-assembled monolayer. The left side of FIG. 2 shows the initial state of the self-assembled monolayer, and the right side shows the state of the self-assembled monolayer with adsorbed copper ions (Cu ²⁺ Adsorption State).
3 is a graph of a change in a voltage signal according to a target ion concentration and time of a liquid sample.
4 is a graph of a change in relative voltage of an ion detection sensor according to the concentration of copper ions and lead ions. The black square is the result of the adsorption of copper ions, the red circle is the result of the adsorption of the lead ions, and the square with the blue frame is the absorption of copper ions in the self-assembled monolayer containing no ion adsorption material (Cu ^{2 +} without T-DETA).
5 is a result of measuring the selectivity of copper ions and lead ions among various ions (Ion Species) of the ion detection sensor. 'Pushing' is a value when a force is applied by the second electrode substrate, and'Releasing' is a value when the force is removed.
6 is a result of measuring the selectivity of copper ions and lead ions in a mixed solution of an ion detection sensor. 'Pushing' is a value when a force is applied by the second electrode substrate, and'Releasing' is a value when the force is removed.
7 is a result of measuring the surface property recovery and reusability through HCl treatment on the substrate of the ion detection sensor. After repeated treatment of copper ions and acids, the average voltage (Normalized Peak Voltage) was measured.
FIG. 8 is a Relative Peak Area at N1 through X-ray photoelectron analysis to determine the number of protons (H ⁺ )-bound amines and the number of copper-ion-bound amines according to an increase in the concentration of exposed copper ions. Is the result of analysis.
9 is a result of analyzing the binding energy (Binding Energy) and signal intensity (Intensity) of copper ions and functional groups according to the concentration of exposed copper ions by X-ray photoelectron analysis.
10 is a graph measuring zeta potential on the surface of a functional group of an ion detection sensor according to a functional group and a copper ion bond. 'PFOTS-SAM' is the result for a self-assembled monomolecular layer containing only a water-repellent coating material,'T-DETA-SAM (Without PFOTS)' is a result of a self-assembled monomolecular layer containing only ion adsorption material, and'Mixed SAM' Is the result for a self-assembled monolayer containing both a water-repellent coating material and an ion-adsorbing material.
11 is a graph measuring the surface potential on the surface of the functional group of the ion detection sensor according to the functional group and copper ion bonding. 'PFOTS-SAM' is the result for a self-assembled monomolecular layer containing only a water-repellent coating material,'T-DETA-SAM (Without PFOTS)' is a result of a self-assembled monomolecular layer containing only ion adsorption material, and'Mixed SAM' Is the result for a self-assembled monolayer containing both a water-repellent coating material and an ion-adsorbing material.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. However, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art. In the drawings, in order to clearly express the constituent elements of each device, the size of the constituent elements, such as width or thickness, is slightly enlarged. Overall, it was described at the observer's point of view when describing the drawings, and if one element is mentioned as being positioned on another element, this means that the one element is positioned directly on another element or that an additional element may be interposed between the elements. Include. In addition, those of ordinary skill in the relevant field will be able to implement the spirit of the present invention in various other forms without departing from the technical spirit of the present invention.

Meanwhile, the meanings of terms described in the present invention should be understood as follows. Terms such as "first" or "second" are used to distinguish one component from other components, and the scope of the rights is not limited by these terms. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

In addition, expressions in the singular should be understood as including plural expressions unless clearly defined otherwise in the context, and terms such as "include" or "have" are described features, numbers, steps, actions, components, and parts. It is to be understood that it is intended to designate the existence of a combination of these and not to preclude the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof. In addition, in performing the method or manufacturing method, each of the processes constituting the method may occur differently from the specified order unless a specific order is clearly stated in the context. That is, each process may occur in the same order as the specified order, may be performed substantially simultaneously, or may be performed in the reverse order. In addition, when a part such as a layer, film, region, or plate is said to be "above or above" another part, this includes not only the case where the other part is "directly above or directly above", but also the case where there is another part in the middle. do. Conversely, when a part is said to be "directly above or directly above" another part, it means that there is no other part in the middle.

In the present invention, "sensor" refers to devices and devices including sensors.

In addition, the'surface treatment' used in the present invention means that a self-assembled monolayer coated with a water-repellent coating material and an ion adsorption material is formed on the insulating layer stacked on the first electrode substrate.

The present invention is a sensor that detects specific heavy metal ions (copper, lead) adsorbed on a solid surface based on a change in an electrical signal generated by a change in the contact area between a liquid and a solid surface through the mechanical motion of a liquid droplet, and heavy metal detection using the same It's about how. Liquid ions can be detected with high selectivity and sensitivity by using the surface properties that change due to the specific adsorption of ions on the solid surface. In addition, it has the advantage that it is possible to generate an electric signal by self-generation and that it can be manufactured in a very simple and inexpensive manner.

The heavy metal ion detection sensor of the present invention utilizes an energy conversion element capable of generating electric energy by changing the contact area of a water droplet by mechanical motion. Referring to FIG. 1, the operation principle of the heavy metal ion detection sensor of the present invention Explain. Figure 1 (a) is to measure the reference signal through the mechanical movement of the heavy metal ion detection sensor in the vertical direction, Figure 1 (b) is the surface exposure of the liquid sample containing the target ions and chemical adsorption in the self-assembled monomolecular layer 1C shows the measurement of a detection signal through vertical motion of a heavy metal ion detection sensor after chemical adsorption. A water droplet containing salt (NaCl 0.01M) is placed between one electrode substrate (upper substrate) and the other insulating film and the electrode substrate (lower substrate) treated with water-repellent/ion adsorption through chemical treatment and placed on both electrode substrates. After connecting an external resistor, a mechanical movement is applied to the upper electrode substrate in a vertical direction. Due to the mechanical movement of the upper electrode substrate, the contact area between the water droplet and the surface-treated lower electrode substrate is changed, and an electrical signal according to the contact area change is observed. At this time, the voltage generated by the device is affected by the movement speed and distance of the upper substrate in the vertical direction, and under certain mechanical motion conditions, the electrical properties (interface potential, interfacial charge density) between the water droplets and the surface of the substrate in the lower substrate are affected. .

In addition, a method of detecting heavy metal ions using the heavy metal ion detection sensor of the present invention will be described with reference to FIG. 1. First, as a reference signal, a water droplet of a reference solution (for example, NaCl aqueous solution) is placed on the upper surface of the lower substrate, and an electric signal generated by applying a constant vertical mechanical motion to the upper electrode substrate is collected. Second, expose the surface-treated electrode substrate located below to a liquid sample (aqueous solution containing copper or lead ions) to be detected for at least 5 minutes. Wash the substrate in sufficiently flowing distilled water and dry it sufficiently through air blowing. Third, as in the first method, a water droplet of a liquid sample is placed on the upper surface of the lower substrate and the electrical signal generated through the mechanical motion of the upper substrate is observed. The degree of adsorption of ions to the surface-treated substrate and the concentration of heavy metal ions (copper or lead ions) in the liquid sample are detected through the rate of change of the electric signal collected in the first and third processes. As described above, the heavy metal ion detection sensor of the present invention can detect heavy metal ions contained in the liquid sample by comparing the reference signal with the electrical signal of the liquid sample and determine the concentration of the heavy metal ion.

The reason that the voltage signal generated by the heavy metal ion detection sensor of the present invention varies depending on the ion concentration exposed to the substrate is a phenomenon due to changes in the electrical properties (surface potential, surface charge density) between the water droplet and the interface of the lower substrate due to ion adsorption. . The voltage measured in the initial state in which ion adsorption did not occur is the adsorbed voltage present in the ion adsorption material ( N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine or N-[3-(Trimethoxysilyl)propyl]ethylenediamine) functional group that induces ion adsorption. This is because the surface potential has a positive potential due to protons (H ⁺ ). However, when the functional group and ions are combined by adsorption of copper ions and lead ions, the positive surface potential decreases due to the decrease in surface proton (H ⁺ ) density, so the voltage signal decreases after ion adsorption (see FIGS. 10 and 11). .

Hereinafter, the heavy metal ion detection sensor of the present invention will be further described.

The present invention is a first aspect, the first electrode substrate; A second electrode substrate facing the first electrode substrate; And an insulating layer formed on the first electrode substrate, wherein the heavy metal ions are detected by an amount of change in electrical energy generated by a change in the contact surface of water or an ionic liquid positioned on the upper surface of the first electrode substrate. It provides a heavy metal ion detection sensor.

In addition, the present invention is a second form, the first electrode substrate; A second electrode substrate facing the first electrode substrate; An insulating layer formed on the first electrode substrate; And a self-assembled monomolecular layer formed on the insulating layer; including, but detecting heavy metal ions by an amount of change in electric energy generated by a change in the contact surface of water or an ionic liquid positioned on the upper surface of the self-assembled monomolecular layer. Provides heavy metal ion detection sensor.

Electrodes used for the first electrode substrate or the second electrode substrate are ITO (Indium Tin Oxide), IGO (Indium Gallium Oxide), chromium, aluminum, IZO (Indium Zinc Oxide), IGZO (Indium Gallium Zinc Oxide), ZnO , ZnO ₂ or TiO ₂ An inorganic electrode containing at least one of platinum, gold, silver, aluminum, iron, or copper, or a metal electrode containing at least one of polyethylenedioxythiophene (PEDOT), carbon nanotubes (Carbon nano tube, CNT), graphene, polyacetylene, polythiophene (PT), polypyrrole, polyparaphenylene (PPV), polyaniline, poly Sulfurnitride, stainless steel, iron alloy containing more than 10% chromium, SUS 304, SUS 316, SUS 316L, Co-Cr alloy, Ti alloy, Nitinol (Ni-Ti) or polyparaphenylene It may be an organic electrode including at least one of vinylene (polyparaphenylenevinylene).

In addition, the first electrode substrate or the second electrode substrate may be a metal substrate, a glass substrate, or a substrate made of a polymer material. Here, the substrate made of a polymer material is polyethylene terephthalate (PET), polyarylate (PAR), polymethylmethacrylate (PMMA), polyethylene naphthalate (PEN), polyethersulfone (Polyethersulfone, It may be a plastic substrate or film including at least one of PES), polyimide (PI), polycarbonate (PC), or fiber reinforced plastics (FRP). In addition, the ceramic substrate may be a substrate using a ceramic material including at least one of alumina (Al ₂ O ₃ ), beryllia (BeO), aluminum nitride (AlN), silicon carbide, mullite, or silicon.

The insulating layer may be formed of a material capable of producing a thin film of a sub-micrometer scale. Specifically, the insulating layer is selected from the group consisting of polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polyvinylphenol (Poly(4-vinylphenol), P4VP), and epoxy-based resins. It is used as an organic polymer insulating layer or semiconductor device formed by any one type, and in any one selected from the group consisting of aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), and hafnium oxide (HfO ₂ ), etc. It may be a metal oxide insulating layer formed by.

The ionic liquid may contain heavy metal ions. The heavy metal ion may be a copper ion or a lead ion. Since the substrate including the self-assembled monolayer has high selectivity and sensitivity to copper ions or lead ions, it can specifically detect copper ions or lead ions.

Meanwhile, in the heavy metal ion detecting sensor of the present invention, a self assembly molecular monolayer may be formed on the insulating layer.

It is preferable that the self-assembled monolayer includes a water-repellent coating material and an ion adsorption material. The self-assembled monomolecular layer may be formed by depositing a water repellent coating material and an ion adsorption material on the insulating layer, and the formed self-assembled monomolecular layer may be represented as shown in FIG. 2. As shown in FIG. 2, the present invention includes both a water-repellent coating material and an ion adsorption material, so that heavy metal ions (copper ions) can be directly bonded to the ion adsorption material. In addition, when an ion adsorption material is selected as a material showing a specific binding to a specific ion, a specific material can be detected with high selectivity.

The water-repellent coating material is a silane-based material, a fluoropolymer material, a trichlorosilane, a trimethoxysilane, a pentafluorophenylpropyltrichlorosilane, and a (benzyloxy) alkyl. Trimethoxysilane ((Benzyloxy)alkyltrimethoxysilane, BSM-22), (benzyloxy)alkyltrichlorosilane ((Benzyloxy)alkyltrichlorosilane, BTS), hexamethyldisilazane (HMDS), octadecyltrichlorosilane , OTS), octadecyltrimethoxysilane (OTMS) and divinyltetramethyldisiloxane-bis-(benzocyclobutene) (Divinyltetramethyldisiloxane-bis(benzocyclobutene), BCB) It may be any one selected from the group consisting of have. The water-repellent coating material facilitates the movement of water droplets.

The ion adsorption material may be N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine) or N-[3-(Trimethoxysilyl)propyl]ethylenediamine. Ions contained in the sample can be adsorbed by the ion adsorption material. In the case of the N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine) and N-[3-(Trimethoxysilyl)propyl]ethylenediamine, copper (II) ions and It has high selectivity for lead(II) ions.

The present invention provides a third aspect, comprising: preparing a first electrode substrate and a second electrode substrate; Stacking an insulating layer on the first electrode substrate; Forming a self-assembled monolayer on the insulating layer; And adsorbing ions onto the upper surface of the self-assembled monomolecular layer by contacting an ionic liquid or water with the upper surface of the self-assembled monomolecular layer. The present invention is capable of self-power generation and does not require external power, and thus a heavy metal ion detection sensor can be manufactured with a very simple configuration, and the manufactured sensor can be miniaturized. In addition, the heavy metal ion detection sensor of the present invention can be reused in acidic conditions.

In a fourth aspect of the present invention, the heavy metal ion detection sensor is used, and after the water is adsorbed on the upper surface of the first electrode substrate, the water and the first electrode substrate are vertically vertically moved. Acquiring an amount of electricity generated according to a change in a contact surface of an upper surface of the electrode substrate; After adsorbing the ionic liquid on the upper surface of the first electrode substrate, the amount of electricity generated according to the change in the contact surface between the ionic liquid and the upper surface of the first electrode substrate by vertical vertical motion of the second electrode substrate is measured. Obtaining; And detecting heavy metal ions by comparing the amount of electricity generated by the water and the amount of electricity generated by the ionic liquid.

Hereinafter, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art.

Example 1: Preparation of heavy metal ion detection sensor

The upper and lower substrates, which are the components of the ion detection sensor, were prepared as indium tin oxide (ITO) glass substrates. ITO was immersed in the solution in the order of a washing solution, acetone, and isopropyl alcohol (IPA) and washed through ultrasonication. To fabricate the lower substrate for ion detection, a PDMS solution diluted in hexane after treatment with O ₂ plasma on the cleaned ITO was spin-coated as an insulating layer. The PDMS insulating layer was cured on a hot plate at 80° C. for about 2 hours. After O ₂ plasma treatment on the PDMS insulating film, a self-assembled molecular monolayer that can easily move water droplets to impart water repellency and induce chemical adsorption of copper ions and lead ions was treated step by step. First, N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine (T-DETA), which induces chemical ion adsorption, was treated in a liquid phase (1 vol% distilled water solution) for 10 minutes. Thereafter, after washing the surface with IPA and distilled water, 1 H , 1 H , 2 H , 2 H -perfluorooctyltriethoxysilane (PFOTS) was treated in the chamber for 30 minutes through thermal vapor deposition (160° C.) for surface water repellency.

Experimental Example 1: Performance check of heavy metal ion detection sensor

(1) heavy metal ion detection

Place a drop (200μL) of NaCl aqueous solution (0.01M) between the untreated ITO substrate (the second electrode substrate) and the surface-treated ITO substrate (the first electrode substrate), and place the two ITO substrates with an oscilloscope. Each of the positive electrodes was bitten to constitute a measurement circuit. Repetitive motion was performed to compress and recover droplets through a constant mechanical motion of the upper substrate (second electrode substrate) in the vertical direction. Specifically, a vertical motion controller capable of controlling motion was used, and the upper substrate reciprocated 2 mm at 2 cm/s, and the final gap between the upper and lower substrates was maintained at 1 mm while the water droplets were pressed. I did. The voltage signal was measured with an oscilloscope through the change in the contact area between the water droplet and the lower substrate. The measured voltage signal was taken as a reference signal. Next, the ITO substrate (first electrode substrate) under chemical surface treatment was recovered and exposed to a detection sample (aqueous solution containing copper ions or lead ions) for about 5 minutes. After that, the surface was dried by simply washing with flowing distilled water and then air blowing. Again, as in the initial measurement process, after installing the ITO board below, the electrical signal was measured. The concentration of copper ions or lead ions in the liquid sample was detected through the ratio of the decreased signal to the reference signal.

As a result of confirmation, as can be seen in FIG. 3, when the ion sensor proposed in the present invention is exposed to copper ions and lead ions, a constant decrease in generated voltage was observed. In addition, as shown in FIG. 4, when the voltage change is calculated as a relative change compared to the initial signal measured value, 4.07×10 ^-3 and 3.02×10 ^-3 μM ^- for copper ions and lead ions in the range of 5 to 100 μM. ^It showed a sensitivity of ¹ .

(2) Check copper ion and lead ion selectivity

In addition to copper ions and lead ions, measurements were performed on potassium ions, magnesium ions, calcium ions, manganese ions, cobalt ions, mercury ions, and nickel ions using the heavy metal ion detection sensor of the present invention. As can be seen in Figure 5, it was possible to confirm the copper ion and lead ion selectivity of about 3.3 to 18 times higher than that of several other competing ions.

(3) Check the copper ion and lead ion selectivity in the mixed solution

In order to confirm the selectivity in the mixed solution of the heavy metal ion detection sensor of the present invention, the performance in the mixed solution in which several ions were mixed was confirmed. The mixed solution used in the experiment was as follows. Solution 1(Na ⁺ , Hg ²⁺ , Co ²⁺ , Cd ²⁺ ), Solution 2(Na ⁺ , Hg ²⁺ , Co ²⁺ , Cu ²⁺ ), Solution 3(Na ⁺ , Hg ²⁺ , Co ^{2 +} , Cu ²⁺ , Pb ²⁺ ). The concentration of each ion was fixed at 100 μM. As a result of the measurement, as shown in FIG. 6, it was confirmed that sufficient performance was shown even in a mixed solution in which several ions were mixed.

(4) Check reusability of heavy metal ion detection sensor

In order to confirm the surface property recovery and reusability of the heavy metal ion detection sensor of the present invention, a cycle of exposing 0.05M HCl to a substrate adsorbed with copper ions (100 μM) for 35 minutes and exposing the copper ions again after measurement was repeated. . As a result of the measurement, as shown in FIG. 7, it was confirmed that the chemically adsorbed ions were desorbed when exposed to an acid solution (HCl 0.05M) for about 35 minutes, and the substrate could be reused about 3 times.

Experimental Example 2: Confirmation of changes in electrical properties at the interface between water droplets and substrate due to heavy metal ion adsorption

In this experimental example, the change in electrical properties at the interface between the water droplet and the substrate due to adsorption of heavy metal ions in the heavy metal ion detection sensor of the present invention was confirmed.

(1) X-ray photoelectron analysis

After exposure of copper ions having concentrations of 0, 40, 100 μM, and 1 mM, they were analyzed by X-ray photoelectron analysis. As a result, as shown in FIG. 8, it was confirmed that the number of proton (H ⁺ )-bound amines decreased and the number of copper-ion (Cu ^{2 +} )-bound amines increased by an increase in the exposed copper ion concentration.

In addition, as a result of confirming the change of the X-ray photoelectron analysis signal of the copper ion due to the combination of the copper ion and the functional group according to the increase in the exposed copper ion concentration, as shown in FIG. 9, Cu 2p _3/2 corresponding to the adsorption state The peak is mainly located near 932 eV, and it was confirmed that the peak shifted from A (931.5 eV) to B (932 eV) depending on the concentration.

(2) Zeta potential and surface potential measurement

In solid-liquid interfaces, accurate and direct measurements of physical parameters such as interfacial potential and charge density are almost impossible. Therefore, zeta potential and surface potential were measured to investigate the change in potential difference for adsorption of copper ions and lead ions.

Specifically, a substrate containing only a water repellent coating material (PFOTS-SAM), a substrate containing only an ion adsorption material (T-DETA-SA (without PFOTS)), a substrate containing both a water repellent coating material and an ion adsorption material (Mixed SAM) The zeta potential was measured after exposing copper ions for each concentration.

10, the zeta potentials of PFOTS and T-DETA-SAM were -14.01 and 20.11 mV, respectively, and the zeta potential of the mixed SAM was 8.00 mV. In the presence of the ion adsorption material, it was confirmed that the zeta potential decreased as the concentration of heavy metal ions increased. In addition, as shown in Fig. 11, it was confirmed that the surface potential also showed the same tendency as the zeta potential. From these results, it was confirmed that the voltage signal changes according to the concentration of heavy metal ions in the liquid sample due to the presence of the ion adsorption material, and the concentration of the heavy metal ions can be measured by the amount of change in the electrical signal through this.

Claims (10)

A first electrode substrate;
A second electrode substrate facing the first electrode substrate;
An insulating layer formed on the first electrode substrate; And
Including; an ionic liquid or water positioned between the first electrode substrate and the second electrode substrate and in contact with the first electrode substrate and the second electrode substrate,
A change occurs in the contact surface of the ionic liquid or water due to the vertical vertical motion of the second electrode substrate,
Heavy metal ion detection sensor to detect heavy metal ions by a change amount of electrical energy generated by the change of the contact surface of the ionic liquid or water. A first electrode substrate;
A second electrode substrate facing the first electrode substrate;
An insulating layer formed on the first electrode substrate;
A self-assembled monolayer formed on the insulating layer; And
Including; an ionic liquid or water positioned between the self-assembled monomolecular layer and the second electrode substrate and in contact with the self-assembled monomolecular layer and the second electrode substrate,
A change occurs in the contact surface of the ionic liquid or water due to the vertical vertical motion of the second electrode substrate,
Heavy metal ion detection sensor to detect heavy metal ions by the amount of change in electrical energy generated by the change in the contact surface of the ionic liquid or water. delete The method according to claim 1 or 2,
The heavy metal ion detection sensor that the ionic liquid contains heavy metal ions. The method of claim 2,
The self-assembled monolayer is a heavy metal ion detection sensor comprising a water-repellent coating material and an ion adsorption material. The method of claim 5,
The ion adsorption material is a heavy metal ion detection sensor that is N ¹ -(3-Trimethoxysilylpropyl)diethylenetriamine) or N-[3-(Trimethoxysilyl)propyl]ethylenediamine. The method of claim 5,
The water-repellent coating material is a silane-based material, a fluoropolymer material, a trichlorosilane, a trimethoxysilane, a pentafluorophenylpropyltrichlorosilane, and a (benzyloxy) alkyl. Trimethoxysilane ((Benzyloxy)alkyltrimethoxysilane, BSM-22), (benzyloxy)alkyltrichlorosilane ((Benzyloxy)alkyltrichlorosilane, BTS), hexamethyldisilazane (HMDS), octadecyltrichlorosilane , OTS), octadecyltrimethoxysilane (OTMS) and divinyltetramethyldisiloxane-bis-(benzocyclobutene) (Divinyltetramethyldisiloxane-bis(benzocyclobutene), BCB) Phosphorus heavy metal ion detection sensor. Preparing a first electrode substrate and a second electrode substrate opposite to the first electrode substrate;
Stacking an insulating layer on the first electrode substrate;
Forming a self-assembled monolayer on the insulating layer; And
Adsorbing ionic liquid or water between the upper surface of the self-assembled monomolecular layer and the second electrode substrate so as to contact the upper surface of the self-assembled monomolecular layer and the second electrode substrate; and a heavy metal ion detecting sensor comprising: Method of manufacturing. The method of claim 8,
The method of manufacturing a heavy metal ion detecting sensor wherein the self-assembled monolayer is formed by coating or depositing a water-repellent coating material and an ion adsorption material on the insulating layer. Using the heavy metal ion detection sensor according to claim 1 or 2,
After adsorbing the water on the upper surface of the first electrode substrate so as to contact the first electrode substrate and the second electrode substrate, the water and the upper surface of the first electrode substrate by vertical vertical motion of the second electrode substrate Obtaining an amount of electricity generated according to the change of the contact surface of the
After adsorbing the ionic liquid on the upper surface of the first electrode substrate so as to contact the first electrode substrate and the second electrode substrate, the ionic liquid and the first Acquiring an amount of electricity generated according to a change in a contact surface of an upper surface of the electrode substrate; And detecting heavy metal ions by comparing the amount of electricity generated by the water and the amount of electricity generated by the ionic liquid.

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