KR102028432B1 - Methods for surface-enhanced Raman scattering using three-dimensional porous nanoplasmonic network - Google Patents

Abstract

The surface-enhanced Raman analysis method using a three-dimensional porous nanoplasmon network, the three-dimensional porous nanoplasmon network structure provided in an aspect of the present invention can be produced by an environmentally friendly material and an economical manufacturing method, solid phase, liquid phase, Not only can the analyte be easily analyzed without distinguishing the gas phase or hydrophilicity or hydrophobicity, but also a lot of metal nanoparticles and analytes may exist in the pores through the laser, which is significantly stronger than the conventional substrate-based optical structure. This has the effect of obtaining a Raman signal.

Description

Method for surface-enhanced Raman scattering using three-dimensional porous nanoplasmonic network

Surface enhanced Raman analysis using three-dimensional porous nanoplasmon network.

As the environmental pollution problem becomes serious, the need for early detection of environmental pollutants such as various heavy metals and organophosphorus compounds is increasing. In addition, as the threat of terrorism increases in the international community, the need for early detection of various bioterrorism substances such as anthrax and sarin is increasing. In addition, there is a growing need to detect biomarkers present in biological samples separated from a subject before the onset of disease in the body and to diagnose and prevent cancer and heart disease with high mortality early.

Therefore, it is very important to detect such dangerous substances quickly and accurately, block their spread, and detect and diagnose biomarkers from patients suspected of having diseases, and trace amounts of such chemicals or biomarkers are very important. The development of analytical technologies has emerged as an important issue in environmental monitoring, forensic science, homeland defense, and healthcare.

Existing analytical technologies such as environmental pollutants or biomolecules not only require complicated pretreatment processes but also require large analytical equipment that is not mobile or very inconvenient, which requires a long time and effort in analysis. .

In this regard, recently, Surface Enhanced Raman Scattering (SERS) has been spotlighted as a method for detecting harmful chemicals and analyzing biomolecules due to its high sensitivity.

In this area, research continues on specific structures that can be used as Raman signal amplification and reliable SERS substrates. For example, to make metal nanoparticles such as gold and silver into a desired shape and shape, ion beam lithography, electron beam lithography, nanosphere lithography and vacuum deposition of metals can be used, or small nanoparticles can be collected in nanocluster form on a substrate. It is used. These techniques are used to create hot spots where the Raman signal can be amplified by controlling the distance between nanoparticles.

However, these technologies are expensive and the manufacturing process is complicated. Techniques for coating silver nanoparticles with silicon nanowire arrays, porous aluminum membranes with gold nanoparticles, and hollow gold nanostructures have been reported to make metal nanostructures for economical, stable and reliable SERS measurements.

Currently, substrates available for SERS have various defects in the enhancement and detection of Raman scattering. Raman scattering signals are generally relatively weak, especially in flat substrates (Patent Document 1). Weak Raman signals make it difficult to detect and identify molecular species present in low concentration samples. Moreover, although the usable substrate enhances the Raman scattering signal, the enhancement of the Raman scattering signal usually occurs in the localized area of the substrate, and for low concentration samples the distribution of molecules present is uniform across the substrate surface. It is difficult to obtain a reproducible Raman signal because it is not adsorbed. The area from which the enhanced Raman scattering signal can be obtained is relatively small compared to the entire area of the substrate surface. Localization of the region from which a Raman scattering signal can be obtained burdens specifying the irradiation position of the laser light to measure the reproducible signal, thus making it difficult to detect and identify molecular species.

Accordingly, there is a need for a new surface enhancement Raman analysis method that can overcome the limitations of the conventional surface enhancement Raman analysis method based on the substrate, and a surface enhancement Raman analysis structure that can be used for such an analysis method.

Republic of Korea Patent Publication 10-2009-0001015

An object in one aspect of the present invention is to provide an optical structure for surface enhancement Raman analysis based on a three-dimensional porous nanoplasmon network.

It is an object of another aspect of the present invention to provide a method for manufacturing the surface enhanced Raman analysis optical structure.

Another object of the present invention is to provide a detection method for determining the presence of an analyte in an analytical sample, using the surface-enhanced Raman analysis optical structure.

In order to achieve the above object,

In one aspect of the invention the matrix of the polymer material with pores formed therein; And

Provided is a surface enhanced Raman analysis optical structure comprising metal nanoparticles dispersed in the matrix.

In addition, in another aspect of the present invention comprising the steps of preparing a template (template) in the form of a water-soluble material;

Immersing the mold in a mixed solution of a first solution containing a polymer material and a second solution containing a metal ion to absorb the mixed solution in the mold;

Curing the polymer material of the mixed solution absorbed into the mold; And

Removing the water-soluble material; provides a method for producing a surface-enhanced Raman analysis optical structure.

Further, in another aspect of the invention, the step of supporting the analysis sample on the surface enhancement Raman analysis optical structure; And

Irradiating laser light is provided, comprising a detection method for determining the presence of the analyte in the analysis sample.

The three-dimensional porous nanoplasmon network structure provided in one aspect of the present invention may be manufactured by an environmentally friendly material and an economical manufacturing method, and easily analyzes analytes without distinguishing solid, liquid, gas, or hydrophilic or hydrophobic properties. In addition to being able to analyze, many metal nanoparticles and analytes may be present in the pores through which the laser passes, thereby achieving a significantly stronger Raman signal than conventional substrate-based optical structures.

1 is an image showing a manufacturing scheme of a three-dimensional plasmon network provided in an aspect of the present invention, the scale bar in Figure 1 represents 2 mm.
Figure 2 is an image showing the results of evaluating the flexibility of the three-dimensional plasmon network provided in an aspect of the present invention.
3 is an image showing the results of evaluating the adsorption characteristics of the three-dimensional plasmon network provided in an aspect of the present invention.
Figure 4 is an image showing the results of evaluating the shape and optical properties of the three-dimensional plasmon network provided in one aspect of the present invention.
Figure 5 is an image showing the results of evaluating the swelling characteristics of the three-dimensional plasmon network or PDMS provided in one aspect of the present invention.
6 is a graph showing a result of comparing the expansion rate by the solvent of the PDMS film and the porous PDMS network.
7 is a graph showing the results of SERS detection evaluation of the three-dimensional plasmon network provided in an aspect of the present invention.
8 is a graph showing the results of systematically measuring the SERS signal of a porous three-dimensional plasmon network prepared at various concentrations of metal precursors, a PDMS base, and a curing agent for optimization.
9 is a graph showing the Raman intensity of adenine, BPE, DCI, and CMIT / MIT low molecular weight using a porous three-dimensional plasmon network as a calibration curve.
10 is an enlarged graph showing the SERS spectrum of the mixed organic compounds.
Fig. 11 is a graph showing the toluene detection result in the gas state using an Ag-plasmon network.

Hereinafter, the present invention will be described in detail.

In one aspect of the invention the matrix of the polymer material with pores formed therein; And

Provided is a surface enhanced Raman analysis optical structure comprising metal nanoparticles dispersed in the matrix.

In this case, the polymer may be used without limitation as long as it is a polymer that can be cured, and in some embodiments, polydimethylsiloxane (PDMS: Polydimethylsiloxane), polyurethane acrylate (PUA: Polyurethane acrylate), and perfluoropolyether ( PFPE: Perfluoropolyether, Polyester acrylate, Polycaprolactone (PCL), Polylactic acid (PLA), Ethylcellulose (EC), Polystyrene (PS: Polystyrene), Polytetrafluoro Polytetrafluoroethylene (PTFE), polypropylene-epoxy, polyalkoxysilane organogels, and the like. These may be used alone or in combination. In one embodiment, since PDMS is hydrophobic, hydrophobic samples can be placed in the network and hydrophilic samples in the pores, so that both lipophilic (hydrophobic) and hydrophilic samples can be measured. The polymer serves to support the surface enhancement Raman analysis optical structure. The polymer matrix may be a sponge type.

In addition, the pores may be an average diameter of 300 to 600 ㎛, but is not limited thereto.

In addition, the metal nanoparticles are plasmon particles that allow the absorption or concentration of light flowing from the outside, and may be used without limitation as long as they are metals commonly used for surface enhancement Raman analysis. ), Silver (Ag) and platinum (Pt) may be used alone or in combination.

In another aspect of the invention comprising the steps of preparing a template (template) in the form of a water-soluble material;

Immersing the mold in a mixed solution of a first solution containing a polymer material and a second solution containing a metal ion to absorb the mixed solution in the mold;

Curing the polymer material of the mixed solution absorbed into the mold; And

Removing the water-soluble material; provides a method for producing a surface-enhanced Raman analysis optical structure.

In preparing a template in the form of a disk (disk) consisting of the water-soluble material, the water-soluble material can be used without limitation, so long as it is a material that is soluble in water, for example, sugar, salt, etc. have. The disk-shaped mold made of the water-soluble material is economically advantageous because it can be prepared by simply molding the water-soluble material. A small amount of water may be used to impart tackiness to the water soluble material when molding the water soluble material.

In the step of absorbing the mixed solution in the mold by immersing the mold in the mixed solution of the first solution containing the polymer material and the second solution containing the metal ion, the metal of the polymer material and the metal ion is as described above. . Metal ions included in the second solution may be present in the form of metal salts such as AgNO ₃ , HAuCl ₄ , H ₂ PtCl _6, and the like. When the mold is immersed in the mixed solution as described above, the mixed solution is injected into the pores formed inside the mold by capillary action. The metal ion concentration of the second solution including the metal ion may range from 1 to 10 mM.

Curing the polymer material of the mixed solution absorbed in the mold may be facilitated by a curing agent. That is, the first solution including the polymer material may further include a curing agent. In this case, the polymer material and the curing agent may be included in the first solution in a weight ratio of 5 to 10: 1. In addition, the curing may be further accelerated by heat-treating the mold in which the mixed solution is absorbed at 40 to 90 ° C.

The curing agent may include an Si—H group, and metal nanoparticles may be formed by reducing the metal ions included in the precursor of the second solution by the Si—H group. As such, as the first solution is cured, the metal ions may be naturally reduced to form nanoparticles, and as a result, the metal nanoparticles may be uniformly dispersed in the polymer matrix. An example of a curing agent may be dimethyl methylhydrogen siloxane (Dimethyl, methylhydrogen siloxane).

Removing the water-soluble material may be carried out by immersing the mold containing the cured polymer material in water to dissolve the water-soluble material in water, but any method that can remove the water-soluble material from the mold without limitation Can be used.

Since the optical structure manufactured in this manner is a porous nanoplasmon structure cured by spontaneous embedding of reduced metal nanoparticles on a polymer in a polymer network, a plurality of metal nanoparticles and analytes may be disposed in a focal volume through which a laser passes. Therefore, the structure is significantly different from the conventional two-dimensional or three-dimensional substrate in that the Raman signal amplification effect by the electromagnetic effect can be largely obtained.

In another aspect of the invention, the step of supporting the analysis sample on the surface enhancement Raman analysis optical structure; And

Irradiating laser light is provided, comprising a detection method for determining the presence of the analyte in the analysis sample.

The method of supporting the analysis sample on the surface-enhanced Raman analysis optical structure may be performed by adsorbing the analysis sample to the optical structure by a physical method. What is necessary is just to contact an optical structure when an analytical sample is a solid state, and to absorb it into an optical structure when an analytical sample is a liquid phase, and to blow a gaseous analytical sample into an optical structure when an analytical sample is a gaseous phase. The laser light can be used without limitation as long as it is a laser light used for Raman analysis, and a specific wavelength range of 400 to 800 nm can be used.

The detection method provided in one aspect of the present invention, if the analyte is hydrophobic (lipophilic), or dispersed in a hydrophobic solvent easily adsorbed to the polymer network, chemical or physical method when the hydrophilic or hydrophilic solvent is dispersed You can simultaneously trap the analyte in the pores.

In addition, due to the three-dimensional porous structure of the optical structure, due to the pore size similar to the laser focal volumn, many nanoparticles and analytes may exist in the light passing portion, thereby maximizing surface enhancement activity only. have.

The three-dimensional porous nanoplasmon network structure provided in one aspect of the present invention may be manufactured by an environmentally friendly material and an economical manufacturing method, and easily analyzes analytes without distinguishing solid, liquid, gas, or hydrophilic or hydrophobic properties. In addition to being able to analyze, many metal nanoparticles and analytes may be present in the pores through which the laser passes, thereby achieving a significantly stronger Raman signal than conventional substrate-based optical structures.

In particular, in the present invention, the Raman analysis was performed by adsorbing a liquid sample to the three-dimensional porous nanoplasmon network, which is an optical structure, and, as a result, does not use a labeling substance, but includes an environmental / biological environment containing not only a Raman active molecule but also a component of a humidifier disinfectant. As a result, the amplified Raman signal for various important molecules can be measured at low concentrations (~ 100 nM).

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

However, the following Examples and Experimental Examples are only illustrative of the present invention in detail, but the present invention is not limited thereto.

Preparation of Experimental Materials

PDMS elastomer kit (Sylgard 184) was purchased from Dow Corning Corporation (Michigan, USA) and prepared. Gold (III) chloride trihydrate (HAuCl ₄ · 3H ₂ O, 48.5%-50.25%), silver nitrate (AgNO ₃ ), crystallized sugar (sucrose, 99.9%), Rhodamine 6G (R6G), NBA perchlorate (nile blue a perchlorate), adenine, 1,2-bis (4-pyridyl) ethylene (BPE), diethyl cyanine iodide (DCI), toluene (C ₆ H ₅ CH ₃ , 99.8%), benzene (C ₆ H ₆ , 99.9%) And 5-chloro-2-methyl-4-isothiazolin-3-one / 2-methyl-4-isothiazolin-3-one (CMIT / MIT) were purchased from Sigma-Aldrich, Missouri, USA and prepared. Cumene (C ₉ H ₁₂ , 95%) was purchased from Acros Organics, Geel, Belgium and prepared. Chloroform (CHCl ₃ , 99%) was purchased from Junsei Chemicals, Tokyo, Japan and prepared. Ethanol (C ₂ H ₅ OH, 95%), sulfuric acid (H ₂ SO ₄ , 95%) and hydrogen peroxide (H ₂ O ₂ , 34.5%) were purchased from Samchun Chemical Co., Seoul, Korea.

< Example  1> Plasmon  network( plasmonic  manufacture of networks 1

For the preparation of plasmon network, granulated sugar crystal templates and PDMS (polydimethylsiloxane) and metal precursor mixed solution were used.

More specifically, the granulated sugar crystals (rectangular form having a short average axial length of about 500 ± 92 μm) are shaped into disks with a few drops of water serving as an adhesive and dried in an oven, A network template was prepared. A gold (Au) aqueous solution was mixed with an uncured PDMS to prepare a base material mixed solution for the preparation of plasmon network. At this time, the uncured PDMS was used Sylgard 184 of Dow, including PDMS monomer and curing agent.

 The network mold made of the sugar was immersed in the base metal mixture solution and degassed for 15 minutes. In this process, the base material mixed solution was absorbed into the network mold made of sugar by capillary action. After degassing, curing was induced for 1 hour at 65 ° C. in an oven to solidify the PDMS network. After complete curing was induced, the solid PDMS was sonicated in water for 30 minutes to dissolve the sugar template. As a result, a three-dimensional porous nanoplasmon network having pores formed therein was prepared. The fabrication scheme of the three-dimensional plasmon network according to Example 1 is shown in FIG.

< Example  2> Plasmon  network( plasmonic  manufacture of networks 2

Instead of using an aqueous solution of gold (Au) ions, the same procedure as in Example 1 was performed except that the aqueous solution of silver (Ag) was used to prepare a three-dimensional plasmon network.

< Experimental Example  1> Physical property evaluation

In order to evaluate the physical properties of the three-dimensional plasmon network prepared in Example 1, the following experiment was performed.

First, in order to evaluate the flexibility of the three-dimensional plasmon network manufactured in Example 1, after confirming that it maintains the shape of the first manufactured state after bending, folding and twisting, it is possible to apply any physical force. The three-dimensional plasmon network prepared in Example 1 was confirmed to be an elastomer (elastomeric) to maintain the original form (Fig. 2).

Next, in order to evaluate the adsorption characteristics of the three-dimensional plasmon network prepared in Example 1, as a result of contacting the liquid or solid powder, the three-dimensional plasmon network prepared in Example 1 was contacted without distinguishing between liquid and solid It was confirmed that the material is easily adsorbed (FIG. 3). In this case, the liquid was dyed with a black dye for the evaluation of the definite adsorption characteristics, the solid powder was used as a white microplastic powder.

From this, it was confirmed that the three-dimensional plasmon network prepared in Example 1 exhibits not only excellent flexibility but also physical properties that can easily adsorb various materials.

< Experimental Example  2> morphology and optical properties evaluation

In order to evaluate the shape and optical properties of the three-dimensional plasmon network prepared in Examples 1 and 2, the following experiment was performed.

First, the three-dimensional plasmon networks prepared in Examples 1 and 2, respectively, were placed on glass slides washed with piranha solution (sulfuric acid: hydrogen peroxide = 7: 3 v / v) for 120 minutes. Example 1, using a dark-field optical microscope (Olympus BX43, Tokyo, Japan) equipped with a hyperspectral imaging spectrophotometer (CytoViva Hyperspectral Imaging System, Auburn, AL, USA) The shape of the three-dimensional plasmon network prepared in 2 was visualized in detail. The scattering spectrum of the network was mapped with a 10 × optical lens. Each spectrum was collected at an exposure time of 0.5 seconds and averaged a total of 50 spectra obtained from the network. The results are shown in FIG.

4A shows a representative shape of the three-dimensional plasmon network prepared in Example 1, (i) is a photographic image, (ii) is an optical image, and (iii) a scanning electron micrograph. )to be. The scale bars are 5 mm (black), 300 μm (red) and 2 μm (white), respectively. From the optical image (ii), it was confirmed that the pore size formed in the three-dimensional plasmon network was 300 to 600 μm on average. From the porometer data B, it was confirmed that 50% of the flow occurred through pores larger than 360 μm, which supports the presence of micropores inside the 3D plasmon network.

4C and 4E are images of the gold (Au) and silver (Ag) -plasmon networks prepared by adjusting the composition and the concentration of the metal precursor, respectively. Specific kinds of the metal precursors used are HAuCl ₄ or AgNO _3, respectively. The metal concentrations of the metal precursors are (i) 1 mM, (ii) 2 mM, (iii) 5 mM and (iv) 10 mM, respectively. The scale bar is 1 cm.

D and F of FIG. 4 are dark-field scattering images of C and E. FIG. The scale bar is 200 μm.

4, G and H show scattering spectra corresponding to C and E. The gold (Au) -plasmon network prepared in Example 1 was found to have a distinct band in the range of 600 to 700 nm, and the silver (Ag) -plasmon network prepared in Example 2 was confirmed to have a spectral peak at about 600 nm. It was confirmed that Example 1 shows a peak in a longer wavelength range than Example 2.

< Experimental Example  3> Evaluation of Swelling properties

In order to evaluate the expansion characteristics of the three-dimensional plasmon network prepared in Examples 1 and 2, the following experiment was performed.

The weight was measured before and after contacting the hydrophilic or hydrophobic solvent with the three-dimensional plasmon network prepared in Examples 1 and 2, or PDMS. Distilled water (DI) or an organic solvent such as toluene, benzene, ethanol was used as the solvent. After incubation for 1 minute, the weight of the network was measured and used to calculate the swelling ratios. In the case of water, O ₂ plasma-treatment was used to use hydrophilic networks, or the water was vigorously vortexed so that the water could be physically trapped in the pores in the network. The plasma-treatment was performed at 100 W for 10 minutes at an oxygen flow rate of 2 sccm. The swelling ratios were calculated through Equation 1 below.

[Equation 1]

In Equation 1,

W _s is the network weight after adsorbing the solvent; And

W _d is the network weight before the solvent is adsorbed.

Using distilled water and organic solvents (toluene, benzene, ethanol), the results of evaluating the inherent expansion characteristics of the porous PDMS structure without metal nanoparticles are shown in Figs.

FIG. 5A shows a representative image before and after toluene treatment of a porous PDMS structure free of metal nanoparticles. From representative images before and after toluene treatment, it was confirmed that the porous PDMS structure produced about 160% volume expansion. On the other hand, from the results of the same experiment using the PDMS film, the PDMS film was confirmed that there is no volume change (Fig. 6). FIG. 5B shows the expansion rate of PDMS observed when toluene, benzene, ethanol, and water were respectively treated in a porous PDMS structure without metal nanoparticles. From FIG. 5B, PDMS easily adsorbed hydrophobic solvents, such as toluene and benzene, and exhibited a significant expansion rate, while ethanol and water, which are hydrophilic solvents, were not easily adsorbed, and the expansion rate was lower than that of hydrophobic solvents. This is also supported by the fact that PDMS exhibits hydrophobic properties. 5C shows before and after treating the water dyed with orange dye to the porous PDMS. From this, it can be seen that the porous PDMS does not easily adsorb water and there is almost no volume change. However, when the porous PDMS is subjected to O ₂ plasma-treatment to impart hydrophilicity or vigorously vortexed water to induce water to penetrate the pores in the porous PDMS, the expansion of PDMS by water may be induced. It was confirmed from the D of FIG.

Next, it was confirmed how the presence of metal nanoparticles in the porous PDMS structure affects the swelling of the composite structure. It was confirmed from E of FIG. 5 that when the gold (Au) -plasmon network prepared in Example 1 was treated with toluene, 170% of volume expansion occurred. Plasmon networks in which gold (Au) or silver (Ag) are present have been identified from F, G and H of FIG. 5 showing a similar trend in toluene or water uptake compared to the porous PDMS structure. Subscripts 1 and 5 in FIG. 5F represent the metal concentration (mM) in the metal precursor.

From this, it was confirmed that the presence or absence of metal nanoparticles does not significantly affect the solvent adsorption capacity of the porous PDMS.

< Experimental Example  4> SERS  Detection evaluation

In order to evaluate the low molecular weight SERS detection evaluation ability of the three-dimensional plasmon network prepared in Examples 1 and 2, the following experiment was performed.

First, for the SERS measurement, a micro-Raman system with a commercial Raman spectrometer SR-303i (Andor Technology), an Olympus BX51 microscope with a 20 × IR (NA = 0.45) objective lens, a 532-nm laser module PSU-III -Changchun New Industries Optoelectronics Technology Co., Ltd. and 785-nm laser module I0785SR0100B1 (Innovative Photonic Solution Inc.) were used. The analyte was prepared with water and ethanol solvent so that it could be easily collected in the porous structure. The hydrophilic solution was adsorbed onto the three-dimensional plasmon network through physical forces such as pipetting or vortexing before SERS measurements. For the analytes R6G, adenine, DCI and BPE, a 785-nm laser was used. For NBA and VOCs, analytes, a 532-nm laser was used. Calibration curves were obtained from the mean spectra collected at 10 locations in the plasmon network at each concentration. 10% ethanol was used to dilute BPE. Four types of VOCs were also tested, including benzene, toluene, cumene and chloroform. To visualize the efficient expansion performance of the plasmon network, benzene was mixed with black ink and dispersed in 100 μM blue-blue NBA aqueous solution to confirm color contrast. 99.9% ethanol was used to dilute cumene.

In addition, a computer-controlled XY precision motorized stage was used to obtain the SERS mapping image. The scan area (1 mm × 1 mm) was divided into acquisition grids of 20 μm in size. All spectra were obtained at an exposure time of 0.1 s with a 785-nm laser operating at 200 mW. Raman intensity maps were derived using signal-tobaseline map generation at 1013 cm ⁻¹ and 1527 cm ⁻¹ for toluene and R6G, respectively.

As shown in FIG. 7A, the three-dimensional plasmon network provides an advantageous SERS active sensing layer in which the metal nanoparticles embedded in the layer and the trapped analyte are within the probe volume of the incident laser. Is placed.

Representative Raman-active dyes, Nile Blue A (NBA) and Rhodamine 6G (R6G), were used to test Raman enrichment by the three-dimensional plasmon networks prepared in Examples 1 and 2, respectively. Taking into account the scattering peaks of the Ag-plasmon network, Raman signals were measured using NBA and 532 nm lasers. The NBA signal of the Ag-plasmon network was found to be 82 times stronger than the signal obtained from the spherical gold nanosphere solution (B) of FIG. 7. For the Au-plasmon network, Raman signals were measured using R6G and a 785 nm laser. As in the previous case, it was confirmed from FIG. 7C that the Au-plasmon network exhibited a significantly enhanced Raman signal when compared to the signal of R6G mixed with the rod gold nanoparticle solution.

For optimization, the SERS signal of the porous plasmon network, prepared at various concentrations of metal precursors and the mixing ratio of the PDMS base and the curing agent, was systematically measured (A and B of FIG. 8). From A of FIG. 8, when AgNO ₃ is used as the metal precursor, the concentration of Ag in the metal precursor is 10 mM, and the Raman strength is the best when the mixed weight ratio of PDMS: curing agent is 5: 1. From FIG. 8B, it can be seen that when HAuCl ₄ is used as the metal precursor, the Raman strength is the best when the concentration of Au in the metal precursor is 2 mM and the mixing weight ratio of PDMS: curing agent is 10: 1.

Intensities were compared at 1647 cm ⁻¹ for NBA and 1377 cm ⁻¹ for R6G. Assay curves were obtained using Ag- and Au-plasmon networks showing the strongest Raman signal (e.g., Au-plasmon networks formed with 2 mM HAuCl ₄ at a 10: 1 PDMS mix ratio) (C to F in Figure 8). .

From C and D of Figure 8, it can be seen that the Raman intensity increases in proportion to the concentration of the analyte NBA, R6G. NBA measured Raman intensity using Ag-plasmon network and 532 nm laser, and R6G measured Raman intensity using Au-plasmon network and 785 nm laser.

E of FIG. 8 represents NBA Raman intensity at 1645 cm ⁻¹ as a calibration curve, and F of FIG. 8 represents R6G Raman intensity at 1377 cm ⁻¹ as a calibration curve. Similarly, it can be seen that the Raman intensity increases in proportion to the concentrations of the analytes NBA and R6G.

Considering the results of FIG. 5, it can be seen that hydrophobic molecules can be intercalated in the PDMS chain, while hydrophilic molecules are trapped in the pores of the plasmon network. Thus, the three-dimensional plasmon network provided in one aspect of the present invention can provide three-dimensional SERS active sensing layers for both hydrophilic and hydrophobic molecules as depicted in FIG. Raman mapping images of Au-plasmon networks sequentially exposed to toluene (hydrophobic) and R6G (hydrophilic) support this feature (E and F in FIG. 7). Scale bars in E and F of FIG. 7 are 200 μm. Both molecules of toluene and R6G can be clearly detected in discrete regions of pores inside the network.

The three-dimensional plasmon network of Examples 1 and 2 provided in one aspect of the present invention may also be used for the detection of small molecules including biomolecules and toxic environmental molecules. Prior to detection, the hydrophilic molecules were dissolved in water or ethanol. Adenine (100 nM) can be detected using the Au-plasmon network according to Example 1 (G in FIG. 7 / A in FIG. 9). SERS signals of BPE (1,2-bis (4-pyridyl) ethylene) and diethyl cyanine iodide (DCI) can be detected at concentrations of 10 nM and 100 nM, respectively (H and I of FIG. 7 / B and of FIG. 9). C). Using the Ag-plasmon network according to Example 2, CMIT / MIT (5-chloro-2-methyl-4-isothiazolin-3-one / 2-methyl-4-isothiazolin-3, a toxic substance used as a humidifier disinfectant) -one) can also be successfully detected below the regulatory level (15 ppm) (J in FIG. 7 / D in FIG. 9).

Detection of volatile organic compounds (VOCs), which are generally hydrophobic, is also possible. It can be seen that VOC tends to assemble at the air / water interface and is easily absorbed in the Ag-plasmon network (K in FIG. 7). It can be seen that the SERS signals of benzene, toluene, cumene and chloroform are very strong and distinguishable from each other (L in FIG. 7). Even when these VOCs are mixed, a single SERS spectrum of the mixture shows a separate peak for each VOC (L / FIG. 7/10). The change according to the concentration of the SERS spectrum for cumene (isopropyl benzene), one of the most dangerous VOCs, was recorded (M in FIG. 7). Linear calibration curves for cumene based on the most prominent peak at 1010 cm ⁻¹ were obtained in the range of 1% to 100% (N in FIG. 7). Using the Ag-plasmon network prepared in Example 2, it was confirmed that detection of the analyte in the gas phase (toluene) is also possible (FIG. 11).

Claims (13)

A matrix of a polymer material having pores having an average diameter of 300 to 600 μm therein; And
Surface-enhanced Raman analysis optical structure comprising the metal nanoparticles dispersed in the matrix.
The method of claim 1,
The polymer is polydimethylsiloxane (PDMS: Polydimethylsiloxane), polyurethane acrylate (PUA: Polyurethane acrylate), perfluoropolyether (PFPE: Perfluoropolyether), polyester acrylate (Polyester acrylate), polycaprolactone (PCL: Polycaprolactone, polylactic acid (PLA), ethylcellulose (EC: Ethylcellulose), polystyrene (PS: Polystyrene), polytetrafluoroethylene (PTFE: Polytetrafluoroethylene), polypropylene-epoxy and polyalkoxy Surface-enhanced Raman analysis optical structure, characterized in that at least one member selected from the group consisting of silane organogel (Poly (alkoxysilane) organogels).
delete Preparing a disk-shaped template made of a water-soluble material;
Immersing the mold in a mixed solution of a first solution containing a polymer material and a second solution containing a metal ion to absorb the mixed solution in the mold;
Curing the polymer material of the mixed solution absorbed into the mold; And
Removing a water-soluble substance; Method of manufacturing an optical structure for surface enhanced Raman analysis.
The method of claim 4, wherein
The water-soluble substance is characterized in that the sugar or salt, surface enhanced Raman analysis optical structure manufacturing method.
The method of claim 4, wherein
The first solution containing the polymer material further comprises a curing agent, surface augmentation Raman analysis method for manufacturing an optical structure.
The method of claim 6,
The polymer material and the curing agent are contained in the first solution in a weight ratio of 5 to 10: 1, Method for producing a surface enhanced Raman analysis optical structure.
The method of claim 4, wherein
The metal ion concentration of the second solution containing the metal ion is 1 to 10 mM, characterized in that the method for producing a surface-enhanced Raman analysis optical structure.
The method of claim 4, wherein
Wherein the curing is characterized in that the heat treatment to the mold absorbed by the mixed solution to 40 to 90 ℃, characterized in that the method for producing a surface enhanced Raman analysis optical structure.
The method of claim 4, wherein
In the step of curing the polymer material of the mixed solution absorbed in the mold,
Metal ion is reduced in the form of metal nanoparticles in the polymer to be cured, surface augmented Raman analysis method for manufacturing an optical structure.
The method of claim 4, wherein
Removal of the water-soluble substance,
A method for producing a surface-enhanced Raman analysis optical structure, characterized in that it is carried out by immersing a mold containing a cured polymer material in water and dissolving the water-soluble material in water.
Supporting an analysis sample on the surface enhanced Raman analysis optical structure of claim 1; And
Irradiating a laser light; detection method for determining the presence of the analyte in the analysis sample.
The method of claim 12,
The laser light has a wavelength of 400 to 800 nm, the detection method for determining the presence of the analyte in the analysis sample.

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