Method for improving sensitivity and selectivity of SERS (Surface Enhanced Raman Scattering) substrate and SERS substrate

Abstract

The invention discloses a method for improving sensitivity and selectivity of an SERS (Surface Enhanced Raman Scattering) substrate and the SERS substrate. According to the method, supramolecules or modified supramolecules with a host-guest effect are combined with noble metal nano sol to be used as the SERS substrate; the supramolecules comprise cucurbituril, pillararene and cyclodextrin; according to the method, after supramolecules are utilized or supramolecular branched chain functional groups are changed into functional groups with amino groups or sulfydryl groups, gaps of noble metal particles are adjusted to nanoscale through branched chain functional groups or modified functional groups on a supramolecular main body, and the purpose of effectively enhancing the SERS electromagnetic enhancement effect is achieved, so that the sensitivity of an SERS method is improved. The supramolecules with unique subject-object recognition capability are applied to Raman detection, and the purpose of capturing and limiting analytes and hot spots can be achieved, so that the selectivity of the method is improved.

Description

(I) Technical field

[0001] The invention belongs to the technical field of Raman spectroscopy, and in particular relates to a method for improving the sensitivity and selectivity of a SERS substrate and a SERS substrate. (II) Background technology

[0002] Surface enhanced Raman spectroscopy (SERS) is a spectroscopy technique that uses the surface plasmon resonance of metal nanoparticles to enhance the Raman signal of molecules adsorbed on the metal nanoparticles, thereby achieving single-molecule SERS. Its enhancement mechanism mainly includes electromagnetic enhancement mechanism (>10 10 ) and chemical enhancement mechanisms (~10-10 4 ). The magnitude of the electromagnetic enhancement mechanism depends on factors such as the material, shape, size, arrangement and dielectric environment of the metal nanoparticles, and is largely affected by the plasma hotspots between the nanoparticles. Studies have shown that ultra-small (about 1nm or less) nanogaps can greatly enhance the electromagnetic field for ultra-sensitive quantitative SERS detection. Therefore, the key to improving the SERS detection signal is to obtain a plasma nanostructure with a strong electromagnetic field by regulating the distance between nanoparticles and to control the number and position of the molecules to be detected in the gap.

[0003] Currently, the methods for regulating the gaps between metal nanoparticles include: forming aggregates by "salting" the metal solvent colloids, which often has poor control over the size, gap and topological structure; forming aggregates by capping with organic monolayers such as DNA, thiol compounds (1,8-hexanedithiol, 6-aminohexanethiol, biphenyl-4,4′-dithiol, (11-mercaptoundecyl)tetra(ethylene glycol)), etc., but they usually exhibit inconsistent and wide particle spacing.

[0004] Macrocyclic host compounds with host-guest interactions (cyclodextrins (CDs), cucurbiturils (CB[n]), calixarenes (CX[n]), pillar[n]arenes (WP[n]), etc.) can achieve self-assembly by mixing nanoparticles with different functionalities or adding additional guest or host molecules. (III) Summary of the invention

[0005] The purpose of the present invention is to provide a method and a SERS substrate for improving the sensitivity and selectivity of a SERS substrate, using supramolecular or modified supramolecular to act on a noble metal nanoparticle sol through chemical bonding, and by functionalizing the supramolecular to bring the metal nanoparticles close to each other, causing aggregation, reducing the gap between the nanoparticles, and confining specific analyte molecules in the hotspot to form a SERS hotspot with a nanogap structure, which is beneficial to improving the intensity and selectivity of the Raman signal, and effectively improving the sensitivity and selectivity of SERS. Since the supramolecular or modified supramolecular can specifically capture the molecules to be detected, specific detection is achieved. The problem that the existing SERS enhancement substrate has low sensitivity to certain low Raman scattering molecules and has large interference in actual sample detection is solved.

[0006] The technical solution adopted by the present invention is:

[0007] The present invention provides a method for improving the sensitivity and selectivity of a SERS substrate, wherein the method uses a supramolecule or a modified supramolecule having a host-guest effect in combination with a noble metal nanosol as a SERS substrate; the supramolecule comprises cucurbituril (CB[8]), pillar aromatic hydrocarbons, and cyclodextrin;

[0008] The modified supramolecular is obtained by changing the functional groups of the supramolecular side chains into functional groups with amino groups or thiol groups, so that the functional groups are connected with the noble metal nanoparticles through coordination.

[0009] Furthermore, when the supramolecular is pillar[5]arene, the modified supramolecular ammonium pillar[5]arene (WP[5]) is prepared as follows: under a nitrogen atmosphere, 1,4-bis(2-bromoethoxy)benzene and polyformaldehyde are dissolved in dichloroethane, stirred for 20 minutes, and then boron trifluoride ether is slowly added. After reacting at room temperature for 1 hour, the solution turns green, methanol is added to the solution to precipitate a white solid, the solution is allowed to stand overnight, and filtered to obtain a white solid product; the white solid product is dissolved in ethanol, 0.3 g / mL trimethylamine ethanol solution is added, refluxed at 90°C for 24 hours, and then the solvent is evaporated to remove, deionized water is added, and filtered to obtain a clear solution, and the water is evaporated to remove the white solid product, which is ammonium pillar[5]arene.

[0010] Furthermore, the mass ratio of 1,4-bis(2-bromoethoxy)benzene to paraformaldehyde is 1:0.1-1.0 (preferably 1:0.18); the volume of ethylene dichloride is 50-100 mL / g (preferably 67 mL / g) based on the mass of 1,4-bis(2-bromoethoxy)benzene; the volume of boron trifluoride ether is 0.5-5 mL / g (preferably 0.8 mL / g) based on the mass of 1,4-bis(2-bromoethoxy)benzene; the volume of ethanol is 200-300 mL / g (preferably 280 mL / g) based on the mass of white solid; the volume of trimethylamine ethanol solution is 5-10 mL / g (preferably 6.4 mL / g) based on the mass of white solid; and the volume of deionized water is 50-100 mL / g (preferably 80 mL / g) based on the mass of white solid.

[0011] Furthermore, the precious metal nanosol includes a gold nanosol, which is prepared as follows: 20 g / L chloroauric acid aqueous solution is added to a flask, followed by ultrapure water, heated to boiling under vigorous stirring at 300-700 rpm (preferably 500 rpm), and then 40 g / L trisodium citrate aqueous solution is quickly added (preferably at a rate of 0.4 mL / s), the color of the solution gradually changes from light yellow to colorless, and finally to wine red. After the color change of the solution stabilizes, condense and reflux for 15 minutes, stop heating, stir and cool to room temperature, and concentrate under reduced pressure to 1 / 5 of the original volume to obtain a gold nanosol.

[0012] Furthermore, the volume ratio of the chloroauric acid aqueous solution to ultrapure water is 2:98, and the volume ratio of the chloroauric acid aqueous solution to the trisodium citrate aqueous solution is 1:1.

[0013] The present invention also provides a SERS substrate prepared by the method, wherein the SERS substrate comprises supramolecules or modified supramolecules and noble metal nanosol.

[0014] The method for detecting analytes by using a SERS substrate of the present invention is as follows: after equal volumes of supramolecular or modified supramolecular aqueous solution and analytes are mixed, the mixed solution is mixed with a noble metal nanosol and then subjected to SERS detection. The analytes include curcumin and estrone.

[0015] Furthermore, the supramolecular or modified supramolecular aqueous solution has a concentration of 0.1-1 mmol / L (preferably 0.1 mmol / L); the analyte is added in the form of its own solution or ethanol solution, and the concentration of the analyte ethanol solution is 0.5-1.5 mmol / L (preferably 1 mmol / L); the volume ratio of the mixed solution to the noble metal nanosol is 1:9-20.

[0016] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0017] (1) The present invention utilizes supramolecules or changes the supramolecule side chain functional groups into amino or thiol-containing functional groups, and adjusts the gap between noble metal particles to the nanometer scale through the side chain functional groups or modified functional groups on the supramolecule body, thereby achieving the purpose of effectively enhancing the SERS electromagnetic enhancement effect, thereby improving the sensitivity of the SERS method.

[0018] (2) The application of supramolecules with unique host-guest recognition capabilities in Raman detection can achieve the purpose of capturing and confining analytes and hotspots, thereby improving the selectivity of the method.

[0019] (3) Since most of the analytes and the dispersants of the metal sols are in aqueous phase, the present invention uses water-soluble supramolecular or modified supramolecular to improve the selectivity and sensitivity of SERS detection, which is of great significance for SERS detection. (IV) Description of the drawings

[0020] Figure 1 , UV-vis spectrum of the SERS substrate prepared in Example 1; curve a represents CB[8] solution, curve b represents Au sol, and curve c represents AuNPs:CB[8].

[0021] Figure 2 , UV-vis spectrum of the SERS substrate prepared in Example 2; curve a represents WP[5] solution, curve b represents Au sol, and curve c represents AuNPs:WP[5].

[0022] Figure 3 , SERS image of the SERS substrate prepared in Example 1 detecting estrogen.

[0023] Figure 4 , SERS image of the SERS substrate prepared in Example 2 detecting estrogen.

[0024] Figure 5 , SERS images of different concentrations of estrogen working solution mixed with AuNPs:CB[8] (A) and estrogen at 714 cm -1 The standard curve of concentration and intensity is shown in (B).

[0025] Figure 6 , SERS images of different concentrations of curcumin working solution mixed with AuNPs:WP[5] (A) and curcumin at 1152 cm -1 The standard curve of concentration and intensity is shown in (B). (V) Specific implementation methods

[0026] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto: the room temperature described in the present invention is 25-30°C.

[0027] Example 1: SERS substrate of gold nanoparticles modified with supramolecular cucurbituril[8]

[0028] (1) Au sol: Take 2 mL of 0.06 mol / L chloroauric acid aqueous solution and add it to a 250 mL flask, then add 98 mL of ultrapure water, heat to boiling under vigorous stirring at 500 rpm, and quickly add 2 mL of 40 g / L trisodium citrate aqueous solution, and add it within 5 seconds. The color of the solution gradually changes from light yellow to colorless, and finally to wine red. After the color change of the solution stabilizes, condense and reflux for 15 minutes, stop heating, and stir and cool to room temperature. Concentrate under reduced pressure to 1 / 5 of the original volume to obtain a nano-gold sol with an average particle size of 20 nm, recorded as AuNPs. The ultraviolet visible spectrum (UV-Vis) is shown in Figure 1 The sample shown in curve b was stored in a 4°C refrigerator for later use.

[0029] (2) AuNPs:CB[8]: Since CB[8] contains carbonyl groups on its ring, it can be chemically bonded to noble metal nanoparticles, so no further modification is required. 20 μL of 0.1 mmol / L CB[8] aqueous solution (UV-Vis Figure 1 The solution was added to 180 μL of AuNPs prepared in step (1) and gently shaken for 10 s to mix the solution thoroughly. The color of the AuNPs solution changed from wine red to blue purple, indicating that the AuNPs were connected by supramolecular chemical bonding to obtain a SERS substrate, denoted as AuNPs:CB[8]. UV-Vis Figure 1 Middle curve c.

[0030] from Figure 1 It can be seen that after the addition of CB[8], the absorbance of AuNPs at 520 nm decreased. At the same time, a new peak appeared at 622 nm, and the color of the solution changed from red to purple, indicating that the addition of CB[8] caused the AuNPs to aggregate and the peak position to red-shift.

[0031] Example 2: SERS substrate of modified supramolecular ammonium column [5] aromatic hydrocarbon-modified gold nanoparticles

[0032] (1) Ammonium pillar [5] arene: In order to achieve the bonding of pillar [5] arene with precious metal nanoparticles, the side chain functional groups need to be modified to prepare ammonium pillar [5] arene. The operation is as follows: Under nitrogen atmosphere, 1.5 g of 1,4-bis (2-bromoethoxy) benzene and 0.278 g of polyformaldehyde are dissolved in 100 mL of dichloroethane. After stirring for 20 min, 1.167 mL of boron trifluoride ether is slowly added. After reacting at room temperature for 1 h, the solution turns green. Methanol is added to the solution to precipitate a white solid. After standing overnight, the solution is filtered to obtain a white solid product. Take the above 0.25 g of the white solid product and dissolve it in 70 mL of ethanol. Add 1.6 mL of 0.3 g / mL trimethylamine ethanol solution. Reflux at 90 ° C for 24 h. Then evaporate the solvent and add 20 mL of deionized water. After filtering, a clear solution is obtained. The water was then removed by evaporation to obtain a white solid product, namely ammonium column [5] aromatics (denoted as WP [5]), which was observed by UV-Vis Figure 2 Curve a in the middle. 1H NMR (400 MHz, Deuterium Oxide) δ 6.88 (s, 10H), 4.48 (s, 20H), 3.92 (s, 10H), 3.70 (s, 20H), 3.23 (s, 90H).

[0033] (2) AuNPs:WP[5]: 25 μL of 10 -4 10 mol / L of WP[5] aqueous solution prepared in step (1) was added to 1 mL of the nano-gold sol synthesized in step (1) of Example 1, and the solution was gently shaken for 10 s to thoroughly mix the solution. The color of the AuNPs solution changed from wine red to purple red and then to blue purple, indicating that the AuNPs were connected through supramolecular chemical bonding to obtain a SERS substrate, which was denoted as AuNPs:WP[5]. UV-Vis Figure 2 Middle curve c.

[0034] like Figure 2 As shown in the figure, the gold nanoparticles have an obvious plasma resonance absorption peak at 520nm, and the half-peak width is relatively narrow. With the addition of WP[5] solution, the characteristic peak of the gold nanoparticles gradually decreases. In addition, a new peak appears at about 680nm. This peak is a manifestation of the aggregation of gold nanoparticles, indicating that within a certain concentration range, WP[5] can regulate the gap between nanoparticles to achieve the purpose of particle aggregation to form hot spots.

[0035] Example 3: Host-Guest Recognition and SERS Enhancement of Supramolecular Cucurbituril[8]

[0036] In Example 1, 0.1 mmol / L CB[8] aqueous solution was mixed with estrone (E1) at a volume ratio of 1:1, and 20 μL was added to 180 μL of AuNPs prepared in step (1) of Example 1. The trace amount of estrogen was detected by SERS. The results are shown in FIG. Figure 3 Middle curve Au+CB[8]+E1.

[0037] 20 μL of estrone was added to 180 μL of AuNPs prepared in step (1) of Example 1, and trace amounts of estrogen were detected by SERS. The results are shown in Figure 3 Middle curve Au+E1.

[0038] 20 μL of the 0.1 mmol / L CB[8] aqueous solution in Example 1 was added to 180 μL of the AuNPs prepared in step (1) of Example 1, and trace amounts of estrogen were detected by SERS. The results are shown in Figure 3 Middle curve Au+CB[8].

[0039] The 0.1 mmol / L CB[8] aqueous solution in Example 1, estrone, and AuNPs prepared in step (1) of Example 1 were used to detect trace amounts of estrogen using SERS. The results are shown in Table 1. Figure 3 Middle curve Au, E1, CB[8].

[0040] Instrument: LabRAM HR UV 800 laser confocal Raman spectrometer (JOBINYVON, France), the laser is He-Ne laser, the laser emission wavelength is 632.18nm, the confocal aperture and grating line number are 300μm and 600lines.mm respectively -1 , the objective lens is a 50x telephoto lens; ADVANCE NEO 400 400MHz NMR spectrometer ( 1 H NMR, Bruker, Germany).

[0041] The confocal Raman microscope spectrum acquisition time was 150s. All measurements were performed at room temperature and the instrument was calibrated with a silicon wafer before testing.

[0042] Depend on Figure 3 It can be seen that the characteristic peak of CB[8] is mainly at 446 cm -1 and 835cm -1 The E1 characteristic peak is located at 714 cm -1 From the curves Au+CB[8]+E1 and Au+E1, it can be seen that before adding CB[8], the SERS enhancement effect of E1 through Au sol is weak, but after adding CB[8], it can be clearly observed that E1 has a strong SERS enhancement effect at 714 cm-1 The characteristic peak intensities at and were significantly enhanced, respectively, by about 19 times. This indicates that the barrel-shaped inner cavity of CB[8] bound to the AuNPs surface can encapsulate estrogen molecules and can play a role in enriching estrogen on the AuNPs surface and around the plasmon hotspots. In contrast to many examples using analytes with high affinity for gold, this effect of CB[8] is particularly important for the detection of analytes with low intrinsic affinity for the gold surface (e.g., estrogen, neurotransmitters).

[0043] Example 4: Host-Guest Recognition and SERS Enhancement of Modified Supramolecular Ammonium Column [5] Aromatic Hydrocarbons

[0044] Curcumin is a naturally abundant pigment with strong hydrophobicity and low water solubility, and the length and width of the curcumin molecular structure are 1.6nm and 0.5nm respectively. Its molecular shape and size are well matched with the structure of the hydrophobic cavity of column [5] aromatic hydrocarbons, providing a molecular basis for the supramolecular effect between them. The curcumin used in this embodiment was purchased from Myril.

[0045] The concentration of 10 prepared in Example 2 -4 mol / L WP[5] aqueous solution and 10 -3 After equal volumes of 10 mol / L curcumin ethanol solutions were mixed, 50 μL was added to 1 mL of AuNPs prepared in Example 1, and curcumin was detected by SERS as described in Example 3. The results are shown in FIG. Figure 4 Middle curve Au+WP[5]+curcumin.

[0046] The concentration of 10 prepared in Example 2 -4 50 μL of mol / L WP[5] aqueous solution was added to 1 mL of AuNPs prepared in Example 1, and curcumin was detected by SERS as described in Example 3. The results are shown in FIG. Figure 4 Middle curve Au+WP[5].

[0047] 10 -3 50 μL of 1 mol / L curcumin ethanol solution was added to 1 mL of AuNPs prepared in Example 1, and curcumin was detected by SERS as described in Example 3. The results are shown in FIG. Figure 4 Middle curve Au+curcumin.

[0048] 10 -3 mol / L curcumin ethanol solution and AuNPs prepared in Example 1 were used to detect curcumin by SERS described in Example 3. The results are shown in FIG. Figure 4 Middle curve curcumin, Au.

[0049] from Figure 4 It can be seen that 1600 to 1630cm-1 The strong peak between 1430 cm and 1440 cm is attributed to the ν(C═O) and ν(C═C) vibrations. -1 The characteristic peak of phenol C–O, the ketoenol form of curcumin is at 1250 cm -1 By comparing the SERS images, after adding WP[5], curcumin has a peak at 1152 cm -1 and 1680cm -1 The characteristic peaks on the left and right have obvious enhancement effects. As blank controls, the gold substrate and column aromatics have no significant effect on the peak intensity, and curcumin itself only has a weak protrusion peak. In summary, WP[5] regulates the nanogap to form hot spots while capturing curcumin to achieve the enhancement of the Raman signal of the analyte.

[0050] Example 5: Quantitative detection of estrogen

[0051] Weigh a certain amount of E1 powder into a beaker and add an appropriate amount of anhydrous ethanol to dissolve it. Transfer the mixed solution to a 10mL volumetric flask to obtain a 0.1mmol / L standard stock solution of estrone. Then, further dilute it step by step with anhydrous ethanol solvent to obtain E1 working solutions with concentrations of 500, 400, 100, 80, 60, 40, 20, 1, and 0.1μmol / L.

[0052] After mixing the E1 working solutions of different concentrations and 0.1 mmol / L CB[8] aqueous solution in equal volumes, 50 μL was added to 1 mL of AuNPs prepared in Example 1 and mixed evenly. The SERS detection Raman spectra described in Example 3 were collected. The results are shown in FIG. Figure 5 Middle A.

[0053] from Figure 5 As can be seen in A, E1 is at 714cm -1 The SERS intensity of the characteristic peak at 714 cm increases with the increase of concentration. The SERS intensity of E1 in the concentration range of 0.1 μmol / L to 20 μmol / L is linear, and the linear equation is I = 0.0487C + 0.4770 (r = 0.9937). -1 The standard curve of concentration and intensity is shown in Figure 5 B. According to the standard of signal-to-noise ratio (S / N=3), the detection limit (LOD) of E1 is 3.75×10 -6 mol / L.

[0054] Example 6: Quantitative detection of curcumin

[0055] Weigh a certain amount of curcumin (purchased from Myrel) into a beaker and add an appropriate amount of anhydrous ethanol to dissolve. Transfer the mixed solution to a 10mL volumetric flask to obtain a 0.1mmol / L standard stock solution of curcumin. Then, further dilute it step by step with anhydrous ethanol solvent to obtain a curcumin working solution with concentrations of 1000, 500, 100, 50, 10, and 1μmol / L, respectively.

[0056] Curcumin working solutions of different concentrations were mixed with 0.1 μmol / L AuNPs:WP[5] prepared in Example 2 in equal volumes, 50 μL of the mixed solution was taken and added to 1 mL of AuNPs prepared in Example 1, mixed and shaken, and detected by SERS described in Example 3. The results are shown in FIG. Figure 6 As shown in A, curcumin was plotted at 1152 cm -1 The standard curve of concentration and intensity is shown in Figure 6 As shown in B. Each concentration gradient was repeated 3 times.

[0057] from Figure 6 A is visible in the middle, 1152, 1482, 1682cm -1 The peaks at the corresponding positions are the characteristic peaks of curcumin, and the intensity of the Raman characteristic peaks of curcumin shows a good positive correlation with the concentration. Figure 6 Medium B, 1152cm -1 The Raman characteristic peak area at is the quantitative peak, and the correlation between the Raman intensity and its concentration in this range is obtained. The linear equation is I = 43758LogC + 198784, R 2 =0.998, indicating that its linearity is relatively good at a certain concentration. According to the standard of signal-to-noise ratio (S / N=3), the detection limit (LOD) of curcumin is 7.55×10 -7 M.

Claims

1. A method for improving the sensitivity and selectivity of a SERS substrate, characterized in that: The method is to use supramolecules or modified supramolecules with host-guest effects in combination with noble metal nanosol as SERS substrates; the supramolecules include cucurbituril, pillar aromatics, and cyclodextrin; The modified supramolecular is obtained by changing the functional groups of the supramolecular side chains into functional groups with amino groups or thiol groups, so that the functional groups are connected with the noble metal nanoparticles through coordination.

2. The method according to claim 1, characterized in that When the supramolecular is pillar[5]arene, the modified supramolecular ammonium pillar[5]arene is prepared as follows: under a nitrogen atmosphere, 1,4-bis(2-bromoethoxy)benzene and polyformaldehyde are dissolved in dichloroethane, stirred for 20 minutes, and then boron trifluoride ether is slowly added. After reacting for 1 hour at room temperature, the solution turns green, methanol is added to the solution to precipitate a white solid, and the solution is allowed to stand overnight, and then filtered to obtain a white solid product; The white solid product was dissolved in ethanol, and a 0.3 g / mL trimethylamine ethanol solution was added. The mixture was refluxed at 90° C. for 24 h, and then the solvent was evaporated to remove it. Deionized water was added and filtered to obtain a clear solution. The water was evaporated to remove it to obtain a white solid product, which was ammonium column [5] aromatic hydrocarbon.

3. The method according to claim 2, characterized in that The mass ratio of 1,4-bis(2-bromoethoxy)benzene to paraformaldehyde is 1:0.1-1.0; the volume amount of ethylene dichloride is 50-100 mL / g based on the mass of 1,4-bis(2-bromoethoxy)benzene; the volume amount of boron trifluoride ether is 0.5-5 mL / g based on the mass of 1,4-bis(2-bromoethoxy)benzene; the volume amount of ethanol is 200-300 mL / g based on the mass of white solid; the volume amount of trimethylamine ethanol solution is 5-10 mL / g based on the mass of white solid; and the volume amount of deionized water is 50-100 mL / g based on the mass of white solid.

4. The method according to claim 1, characterized in that The noble metal nanosol includes gold nanosol.

5. The use according to claim 4, characterized in that The gold nanosol is prepared as follows: 20 g / L chloroauric acid aqueous solution is added to a flask, followed by ultrapure water, and heated to boiling under vigorous stirring at 300-700 rpm, and then 40 g / L trisodium citrate aqueous solution is quickly added, and the color of the solution gradually changes from light yellow to colorless and finally to wine red. After the color change of the solution stabilizes, condensation reflux is performed for 15 minutes, heating is stopped, stirring is performed to cool to room temperature, and reduced pressure concentration is performed to 1 / 5 of the original volume to obtain the gold nanosol.

6. The use according to claim 5, characterized in that The volume ratio of the chloroauric acid aqueous solution to ultrapure water is 2:98, and the volume ratio of the chloroauric acid aqueous solution to trisodium citrate aqueous solution is 1:

1.

7. A SERS substrate prepared by the method of claim 1.

8. A method for detecting an analyte using a SERS substrate prepared by the method of claim 1, the method comprising: mixing equal volumes of a supramolecular or modified supramolecular aqueous solution and an analyte, and then mixing the mixed solution with a noble metal nanosol and performing SERS detection.

9. The method according to claim 8, characterized in that The analytes include curcumin and estrone.

10. The method according to claim 8, characterized in that The supramolecular or modified supramolecular aqueous solution has a concentration of 0.1-1 mmol / L; the analyte is added in the form of its own solution or ethanol solution, and the concentration of the analyte ethanol solution is 0.5-1.5 mmol / L; the volume ratio of the mixed solution to the noble metal nanosol is 1:9-20.

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