KR20070026909A - Chip for the detection of polychlorinated biphenyl using surface plasmon resonance measurements - Google Patents

Abstract

A chip for detecting polychlorinated biphenyl(PCB) is provided to show high selectivity on the PCB, be able to detect the PCB with very low concentration, and be utilized for a surface plasmon resonance device. The chip for detecting PCB includes a transparent support layer, an Au thin film layer prepared by coating Au on one side of the transparent support layer, and a self-assembled mono-molecule layer formed on the Au thin film layer by an alkane compound including thiol groups on both ends thereof such as 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,7-heptanedithiol, and 1,8-octanedithiol.

Description

Chip for detecting polychlorinated biphenyl using surface plasmon resonance device {CHIP FOR THE DETECTION OF POLYCHLORINATED BIPHENYL USING SURFACE PLASMON RESONANCE MEASUREMENTS}

1 is a cross-sectional view showing a chip for detecting polychlorinated biphenyl (PCB) according to the present invention.

2 is a schematic diagram showing a surface plasmon resonance device for sensing a chip for detecting polychlorinated biphenyl (PCB) according to the present invention.

3 is a graph showing a result of detecting a PCB using a polychlorinated biphenyl (PCB) chip according to the present invention in real time.

Figure 4 is a graph showing the results of detecting the PCB 8ppb using a polychlorinated biphenyl (PCB) chip according to the present invention.

Figure 5 is a graph showing the function of the change in the surface plasmon resonance angle according to the PCB concentration using the polychlorinated biphenyl (PCB) chip according to the present invention.

<Description of the symbols in the main part of the drawing>

1: transparent support layer 2: chromium layer

3: gold thin film layer 4: self-assembled monolayer

5: laser light source 6: signal detector

7: Sample cell 8: Prism

9: chip for PCB detection

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip for detecting polychlorinated biphenyls (PCBs) using Surface Plasmon Resonance measurements (SPR measurements), in particular alkane on a film coated with a gold thin film. By forming a self-assembled monolayer by using a compound, the present invention relates to a chip for PCB detection with excellent detection of PCB.

Here, the surface plasmon resonance (SPR) phenomenon is a collective vibration of electrons occurring on the surface of the metal thin film, and the surface plasmon waves generated by this are surface electromagnetic waves which propagate along the interface between the metal and the adjacent dielectric material. To detect specific contaminants in surface plasmon resonance (SPR) devices, one of the signal conversion techniques for analyzing nanoscale interface phenomena.

Recently, the damage caused by PCB as an environmental pollutant has been frequently reported. PCB refers to a substance in which one or more hydrogen atoms are substituted with chlorine in a biphenyl group (C ₁₂ H ₁₀ ), and there are theoretically 209 isomers depending on the number and position of substituted chlorine (1 to 10).

These PCBs have been usefully used as insulating oils in various electrical products, but their use has been restricted internationally through the Stockholm Convention because they have a serious adverse effect such as causing environmental pollution and destroying the human immune system. . Therefore, a method of detecting such a PCB has emerged as an important method, and in particular, since contamination occurs frequently through wastewater or soil, a detection method in an aqueous solution is required.

Although it has not yet been used in the industry as a detection sensor of such a PCB, it is disclosed in Korean Patent Laid-Open Publication No. 1992-0016205 for waste water treatment method and Korean Patent Laid-Open Publication No. 1997-0069074 for a method for recovering a conventional water-soluble contaminant. It is becoming. Here, there is a method of removing sludge from the water-soluble resin or the sedimentation basin, but there is a problem that the selectivity for a particular contaminant such as ionic form or PCB is significantly reduced.

Meanwhile, as a method for detecting a specific contaminant in an aqueous solution, Korean Patent Publication No. 2002-0038222 describes a device for detecting chromium in wastewater, and Korean Patent Publication No. 2002-0007256 discloses nitrogen and phosphorus in wastewater. Methods for detecting are described. However, this method also has a limit to detect when there is a very small amount of organic substances dissolved in an aqueous solution, there is a problem that the device is so large that its utility as a small sensor chip is poor.

Therefore, PCBs, which have recently emerged as serious environmental contaminants, have very low solubility (ppb units) in aqueous solution, and therefore, a device for detection at very low concentrations is needed. Therefore, research on small sensor chips that can be utilized in various industries is required in accordance with the development trend of nanotechnology.

Therefore, the present invention for solving this problem, by coating a thin gold film on a high transparent support layer of silica material, by forming a self-assembled monomolecular layer using an alkane compound, surface Plasmon Resonance (SPR) phenomenon It is an object of the present invention to provide a chip for detecting a PCB that has high selectivity with respect to a PCB, which is a target detection material, and can be detected at a very low concentration, which can be used for a surface plasmon resonance (SPR) device.

PCB detection chip of the present invention for achieving the above object, a transparent support layer, a gold thin film layer coated with gold (Au) on one side on the transparent support layer and a thiol group at both ends on the gold thin film layer It comprises a self-assembled monolayer formed of an alkane compound containing (SH).

The present invention first revealed the mutual bonding force between the PCB and the thiol group (SH), which has not been studied yet, to provide a molecular recognition sensor chip such as a PCB using a surface plasmon phenomenon.

Here, the surface plasmon resonance (SPR) phenomenon is a collective vibration of electrons occurring on the surface of the metal thin film as described above, and the surface plasmon wave generated by the surface plasmon resonance is a surface electromagnetic wave propagating along the interface between the metal and the adjacent dielectric material. The present invention aims to detect specific contaminants in a surface plasmon resonance device, which is one of signal conversion techniques for analyzing nanoscale interface phenomena.

In detail, self-assembly of alkane compounds having a thiol group (SH) as an end group capable of molecular recognition of PCBs on a thin film of gold (Au), a metal that generates surface plasmon waves, leads to self-assembly. This is to detect the PCB which is dissolved in trace amount in aqueous solution by using surface plasmon resonance (SPR) device to signal nano level signal (combination of PCB and thiol group).

Here, the transparent support layer included in the present invention is preferably a silica material as shown in Figure 1, in detail, when used in a surface plasmon resonance (SPR) device is preferably a glass of SF10 or BK7 material. The reason is that the material is the same as the prism of the surface plasmon device to be used in the present invention. When the material is used, the surface plasmon (SPR) resonator is used in various media (air, aqueous solution, organic solvent, etc.). This is because the surface plasmon resonance (SPR) angle can be measured.

Specifically, in the present invention, it is preferable to use gold (Au, purity of 99.9% or more) as a metal capable of generating surface plasmon waves and measuring surface plasmon resonance angles. This is because gold thin films are easy to form self-assembled monolayers for organic functional groups that are selective for the detection of contaminants and are advantageous metals for generating surface plasmon waves.

Meanwhile, it is preferable to further layer a chromium (Cr) layer between the transparent support layer and the gold thin film layer. In this case, the chromium layer 2 serves as an adhesive between the transparent support layer 1 and the gold thin film layer 3 and has an advantage of preventing reuse of the chip surface when used as a sensor chip.

The thickness of this chromium layer is preferably 3 to 10 nanometers. This is because it is an appropriate thickness for forming the surface plasmon wave of the metal while serving as an adhesion with the gold thin film layer.

Here, the gold thin film layer 3 can be deposited directly on the transparent support or, if desired, on the chromium layer 2, with a thickness of 10 to 100 nanometers. If the thickness is smaller than 10 nanometers, the thickness of the thin film is difficult to form, and if larger than 100 nanometers, there is a problem that is not economical in the absence of an improved effect. For this reason, the thickness of the gold thin film layer is preferably 40 to 60 nanometers.

The chromium layer 2 and the gold thin film layer 3 are sequentially stacked on one side of the transparent support layer 1, and thermal evaporation is preferable. This is because it is a suitable way to coat metal to the nano level above, which is a suitable way to measure the surface plasmon resonance angle when using a surface plasmon resonance (SPR) device.

On the other hand, the self-assembled monomolecular layer 4 introduced on the thus formed gold thin film layer 3 includes a self-assembled monomolecular layer 4 formed of an alkane compound containing thiol groups SH at both ends. The self assembled monolayer (SAM) refers to a monomolecular layer in which the organic molecules constituting the alkane compound are regularly well aligned by spontaneous chemical bonding on the surface of the substrate.

It is preferable to use an alkane compound containing a thiol group (SH) at both ends, since one of the thiol groups (SH) shows a well-ordered surface structure with a crystalline metal such as gold (Au). This is because it is suitable for forming the self-assembled monolayer 4 above. In addition, the other thiol group (SH) is intended to induce an adsorption bond with a PCB, which is a hazardous organic substance of interest in the present invention.

Specifically, as an alkane compound containing a thiol group (SH) at both ends, 1, 3-propanedithiol (1,3-Propanedithiol), 1,4-butanedithiol (1,4-Butanedithiol), 1, 5-pentanedithiol (1,5-Pentanedithiol), 1,6-hexanedithiol (1,6-Hexanedithiol), 1,7-heptanedthiol (1,7-Heptanedithiol), 1,8-octanedithiol At least one material selected from the group consisting of (1,8-Octanedithiol) is preferably used as the self-assembled monolayer (SAM) of the present invention. This is because the alkane compound is an appropriate carbon chain length in which self-assembly is stable when the self-assembled monomolecular layer is formed on the gold thin film layer.

Specifically, when the carbon chain is too short, the time required to form the self-assembled monolayer (SAM) becomes very long, such as 24 hours or more. There is an unfavorable problem. In addition, when the chain length of the alkane compound is too long, there is a problem in that the tilting (tilting) occurs between the alkane compound molecules and also the stability is inferior. For this reason, 1,6-hexanedithiol (1,6-Hexanedithiol, HDT) is preferred as the appropriate chain length to form the self-assembled monolayer (SAM) of the present invention.

This self-assembled monomolecular layer 4 is formed by preparing the appropriate alkane compound in an aqueous solution or an ethanol solution and soaking the glass coated with the gold thin film layer 3 for several hours. Specifically, the concentration of the aqueous solution and the ethanol solution is preferably 1 to 10 mM, and the production time is preferably 5 hours to 20 hours.

This is because the stability of the self-assembled monolayer 4 is the best in the above time range. This manufacturing method is a chemical bond is formed by the self-assembly of the alkane compound, and does not require an additional chemical process, and is formed at room temperature and normal pressure, and thus undergoes a very simple process compared to the conventional technology.

The PCB detection chip according to the present invention can measure the surface plasmon resonance angle through the surface plasmon resonance (SPR) device of FIG. 2, and can detect the PCB detection through the change of the surface plasmon resonance (SPR) angle. have. In detail, the heavy metal detection chip between the prism 8 and the sample cell 7 is a liquid of an index matching fluid having the same prism, the transparent support 1, and the refractive index (n _D = 1.755 ± 0.005). Fix it.

Therefore, the surface plasmon resonance phenomenon (SPR) generated by chemical coupling with the target PCB contained in the sample cell 7 generated on the surface of the PCB for detecting the chip of the present invention as the light from the laser light source 5 is amplified through the lens. The change of can be observed through the signal detector (6). At this time, the PCB detecting chip and the sample cell 7 which are in close contact with the prism 8 are integrally rotated in the circular shape of FIG. 2 to find the surface plasmon resonance (SPR) angle.

This transmits and receives data from the light source 5 through the signal detector 6 connected to the computer to change the amount of reflected light generated according to the surface change of the PCB detection chip. The method of detecting the target PCB through the surface plasmon resonance (SPR) device can be measured by the following two methods.

The first method is to find the surface plasmon resonance angle before the detection of the integrated type of the PCB detection chip and the sample cell (7) in close contact with the prism (8), fix the angle and then place the PCB in the sample cell (7) And the chemical change occurring on the surface between the PCB detection chip of the present invention through the signal detector 6 in real time. Through this, it is possible to know how many hours the chemical bond between the target material and the detection chip is stabilized, and this is measured through the change of the reflected light reflected from the chip surface.

The second method, unlike the first method, is a method of scanning the reflected light reflected on the surface of the chip as the integrated unit of the PCB detecting chip and the sample cell 7 in close contact with the prism 8 is rotated. Through this, the surface plasmon resonance angle (SPR angle) is found.

In other words, it is possible to determine whether the PCB is detected by measuring the difference (SPR angle change) of the surface plasmon resonance angle before and after the PCB detection on the PCB detection chip surface. In addition, the difference in the surface plasmon resonance angle is observed for each concentration of the aqueous phase of the PCB, it can be detected by the concentration of the target pollutant.

Therefore, when the PCB detection chip of the present invention using the surface plasmon resonance device is used, since the intermolecular interaction of several nano-sized levels occurring on the surface is detected through the change of the surface plasmon resonance angle, the concentration in the aqueous solution is very low. There is a big advantage to detect the PCB.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The following examples are intended to illustrate the invention, but are not limited to these.

Example 1

5 nm of chromium and 50 nm of gold were deposited on a SF10 (Fisher Scientific) high transparent glass support having a width of 2.5 cm and a height of 1.5 cm by thermal evaporation (using AUTO306 Edwards). The gold thin film thus prepared was immersed in 1,6-hexanedithiol (1,6-Hexanedithiol, HDT, Sigma-Aldrich) ethanol solution having a concentration of 1 mM at room temperature and atmospheric pressure for 18 hours, and then washed with ethanol. After drying with a nitrogen gun to prepare a PCB for detecting the chip to form a self-assembled monolayer (4).

The chip thus prepared is fixed to the surface plasmon resonance apparatus of FIG. 2 using an index matching fluid, and then a PCB (Aroclor 1248, biphenyl tetrachloride, SUPELCO company) is attached to the sample cell 7. ) After the injection of an aqueous solution of 8 ppb (because it is the maximum solubility in the aqueous phase at room temperature and atmospheric pressure), the first method is to fix the angle and reflect the PCB surface interaction with the PCB in real time. The change in the amount of light (Delta Reflectance) was measured.

This result is shown in FIG. 3. As shown in FIG. 3, it can be seen that the signal change reaches equilibrium in about 2 hours, which means an equilibrium time according to the interaction between the PCB and the surface of the manufactured PCB detection chip. Therefore, in the following examples, in order to measure the difference between the surface plasmon resonance angles before and after PCB detection on the PCB detection chip surface, a time difference of 2 hours or more, that is, 6 hours was selected and compared.

Example 2

5 nm of chromium and 50 nm of gold were deposited on a SF10 (Fisher Scientific) high transparent glass support having a width of 2.5 cm and a height of 1.5 cm by thermal evaporation (using AUTO306 Edwards). The gold thin film thus prepared was immersed in 1,6-hexanedithiol (1,6-Hexanedithiol, HDT, Sigma-Aldrich) ethanol solution having a concentration of 1 mM at room temperature and atmospheric pressure for 18 hours, and then washed with ethanol. After drying with a nitrogen gun to prepare a PCB for detecting the chip to form a self-assembled monolayer (4).

The chip thus prepared was fixed to the surface plasmon resonance apparatus of FIG. 2 by using an index matching fluid, and then 8 parts of PCB (Aroclor 1248, biphenyl tetrachloride, SUPELCO Co., Ltd.) aqueous solution was added to the sample cell 7. After 6 hours, the PCB aqueous solution of the sample cell 7 was removed, and the change in the surface plasmon resonance angle before and after PCB detection in air was measured.

The result of the change of the angle is shown in Table 1 and FIG. Referring to FIG. 4, the angle corresponding to the point where the reflected light amount is the minimum means the surface plasmon resonance angle, and it may be determined whether the PCB is detected through the difference.

Example 3

A PCB detection chip was manufactured in the same manner as in Example 2, except that 1 ppb of PCB solution was used as the target detection solution, and the same process was performed. The results are shown in Table 1 below.

Example 4

A PCB detection chip was manufactured in the same manner as in Example 2, except that 0.1 ppb of PCB solution was used as the target detection solution, and the same process was performed. The results are shown in Table 1 below.

Example 5

A PCB detection chip was manufactured in the same manner as in Example 2 except that the PCB solution of 0.01 ppb was used as the target detection solution, and then the same process was performed. The results are shown in Table 1 below.

Example 6

A PCB detection chip was manufactured in the same manner as in Example 2 except that the PCB aqueous solution having a concentration of 0.001 ppb was used as the target detection solution, and then the same process was performed. The results are shown in Table 1 below.

[Table 1] PCB detected using surface plasmon resonance (SPR) device

 Surface Plasmon Resonance Angle Variation [degree]   PCB detection chip      Example 2 0.22      Example 3 0.17      Example 4 0.15      Example 5 0.11      Example 6 0.06

As shown in Table 1, the surface plasmon resonance (SPR) device has the advantage that can detect very minute changes in the surface of the chip prepared in the present invention is a very low concentration PCB having a PCB aqueous solution concentration of 0.001 ppb It can be seen that the surface plasmon resonance angle change was detected.

Here, the smaller the value of the resonance change (SPR) of the surface plasmon means that the PCB concentration in the PCB detection chip manufactured in the present invention is hardly detected because the concentration of the PCB is very low. These results are shown as a graph of the change in the surface plasmon resonance angle according to the PCB concentration as shown in FIG. The x axis at this time represents the logarithmic scale of the PCB concentration.

As described above, the PCB is a detection chip using the surface plasmon resonance (SPR) device according to the present invention, which can be detected in real time even at a very low concentration, and reveals the interaction between the PCB and the thiol group (SH) for the first time, and the nano technology. As a small sensor in the industry based on the high availability is very effective.

PCB detection chip according to the present invention can be modified and applied in various forms within the scope of the technical idea of the present invention is not limited to the above preferred embodiment. In the above embodiment, 1,6-hexanedithiol (1,6-Hexanedithiol, HDT) as a compound used for the self-assembled monolayer 4, and the case of biphenyl tetraphenyl as the detection PCB, but the technical It is not intended to limit the scope of the idea, and unlike the examples, there are more compounds for performing various functions, and variations in concentration or preparation time will be considered merely modifications of the present invention. In addition, the chip for detecting a PCB according to the present invention will be applicable to other isomers as a target detection PCB.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. Of course, it is not limited to, but should be determined to include the claims and equivalents as well as the claims to be described later.

As described above, the polychlorinated biphenyl (PCB) detection chip of the present invention is coated with a thin film of gold on a highly transparent support layer, and then contains an alkane compound containing a thiol group (SH) at both ends. By using a self-assembled monolayer (SAM) to form a self-assembled monolayer (SAM), high selectivity for the target detection material PCB, it can be detected in a very low concentration in real time can be utilized in surface plasmon resonance (SPR) device In addition, it is effective to provide a chip for detecting a nano-level molecule recognition PCB.

Claims (5)

A transparent support layer, a gold thin film layer coated with gold (Au) on one side on the transparent support layer, and a self-assembled monomolecular layer formed of an alkane compound containing thiol groups (SH) at both ends on the gold thin film layer. Polychlorinated Biphenyl (PCB) detection chip, characterized in that. The method of claim 1, Chips for detecting polychlorinated Biphenyl (PCB), characterized in that the chromium layer is laminated between the transparent support layer and the gold thin film layer. The method of claim 1, The gold thin film layer is a polychlorinated Biphenyl (PCB) detection chip, characterized in that the thickness of 10 to 100 nanometers. The method of claim 2, The chromium layer is a polychlorinated Biphenyl (PCB) detection chip, characterized in that the thickness of 3 to 10 nanometers. According to claim 1, wherein the self-assembled monolayer is a 1,3-propanedithiol (1,3-propanedihiol), 1,4-butanedithiol (1,4-Butanedithiol), 1,5-pentanediyl alkanes Ol (1,5-Pentanedithiol), 1,6-hexanedithiol (1,6-Hexanedithiol), 1.7-heptanedthiol (1,7-Heptanedithiol), 1,8-octanedithiol (1,8-Octanedithiol Polychlorinated Biphenyl (PCB) detection chip, characterized in that formed from one or more materials selected from the group consisting of.

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