A method for chiral recognition of phenylalanine

Abstract

This invention provides a method for chiral recognition of phenylalanine, comprising the following steps: (1) preparing a ReSe2 film using NH4ReO4, NaCl, and selenium powder; (2) preparing gold nanoparticles using HAuCl4, NaBH4, and CTAB and AA at different concentration ratios, and inducing the formation of gold nanoparticles with different chiralities by adding cysteine ​​solutions; (3) dropping the prepared gold nanoparticle colloids with different chiralities onto the above ReSe2 film, and after complete air drying, dropping in a concentration range of 10 ‑3 -10 ‑7 (4) Using a fully automated laser confocal micro Raman spectrometer, Au-ReSe2 substrate materials loaded with phenylalanine of different chiralities were tested. This invention can achieve sensitive detection at a specific deflection angle, and at the same time, through the interaction between the enantiomer and the specific chiral substance, it exhibits a certain difference, which not only enhances the Raman signal, but also achieves good detection range for low concentrations of Phe (10 mol / L). ‑3 -10 ‑7 It has the advantages of strong molecular signal and wide detection range, with chiral recognition capability of mol / L.

Description

Technical Field

[0001] This invention relates to the fields of nanomaterials, laser Raman spectroscopy, and chiral recognition, and specifically to a novel SERS method for recognizing the enantiomer of phenylalanine from Au-ReSe2 chiral plasmon structures. Background Technology

[0002] Enantiomerism is a common phenomenon in chemistry, where one enantiomer and its corresponding counterpart are identical in many properties. However, their differences in efficacy within biological systems have attracted considerable attention, making enantiomer identification a crucial task in fields such as drug screening, diagnostics, and environmental monitoring. Circular dichroism spectroscopy (CD) is a commonly used method for resolving enantiomers, but it typically requires high sample concentrations or long optical path lengths to obtain observable CD signals. More importantly, CD detection fails at low sample concentrations. Therefore, alternative spectroscopic methods are needed to overcome these shortcomings of CD spectroscopy. Surface-enhanced Raman scattering (SERS) spectroscopy is a promising area in this regard. SERS offers numerous advantages, such as fast detection speed and high sensitivity, and it is highly sensitive to intermolecular interactions by monitoring changes in the vibrational fingerprint information of molecules. However, existing SERS-prepared surface-enhanced Raman scattering substrates rely on indirect detection using other selectors for chiral identification, resulting in poor molecular signals, a limited detection range, and an inability to leverage the key advantages of SERS for single and universal chiral differentiation.

[0003] Enantiomers can exhibit certain differences when interacting with specific chiral substances. SERS spectroscopy can be used to observe these differences, thus enabling enantiomer differentiation. L-phenylalanine (L-Phe) is one of the essential amino acids for the human body, involved in eliminating the functional waste of the kidneys and bladder. D-phenylalanine (D-Phe), while not an essential amino acid for life activities, can inhibit the degradation of enkephalins (an endogenous analgesic substance) by inhibiting the activity of carboxypeptidase, thereby exerting an analgesic effect. Therefore, the development of a chiral recognition method for phenylalanine is of great significance.

[0004] Anisotropic two-dimensional materials (TMDs), represented by rhenium diselenide (ReSe2), are currently the most widely studied two-dimensional honeycomb structure compounds. However, unlike isotropic two-dimensional materials, ReSe2 is a semiconductor with an untunable bandgap; the bandgap width is not affected by the number of layers. This bandgap variation endows it with unique optical, electrical, and optoelectronic properties, making it applicable to lithium-ion batteries, logic devices, novel optoelectronic sensors, and logic data storage. Furthermore, in addition to its conventional optoelectronic properties, ReSe2 exhibits anisotropic characteristics. Simply put, if measurements are taken along different directions of a hexagonal ReSe2 structure, significantly different performance data can be obtained.

[0005] The fabrication and chiral differentiation of chiral substrate materials based on nanoparticles (NPs) have been found to play a unique role. In previous studies, NPs have been applied to several methods for enantiomeric recognition, yielding ideal experimental results regarding chiral molecular configuration and enantiomeric purity. The easily tunable physical and chemical properties of NPs, and the ability to functionalize their surfaces with molecules of different properties, provide a suitable sensing platform for chiral recognition. Summary of the Invention

[0006] The purpose of this invention is to provide a method for chiral recognition of phenylalanine. This method utilizes anisotropic two-dimensional materials, such as ReSe2, for polarization detection, achieving sensitive detection at specific deflection angles. Simultaneously, chiral AuNPs are used as carriers to adsorb phenylalanine molecules. Through the interaction between enantiomers and specific chiral substances, certain differences can be observed, which not only enhances the Raman signal but also achieves good detection range for low concentrations of Phe (10⁻⁶). -3 -10 -7 Chiral recognition ability (mol / 1).

[0007] The technical solution of this invention is implemented as follows:

[0008] This invention provides a method for chiral recognition of phenylalanine, comprising the following steps:

[0009] (1) Take NH4ReO4 and NaCl powder, add organic solvent, ball mill and centrifuge to dry, to obtain a mixture of NH4ReO4 and NaCl; place the mixture in a tube furnace, place a single-layer polished alumina substrate 5-10 mm away from the mixture, and introduce Ar / H2 as carrier gas to heat and react selenium powder and NH4ReO4 in the tube furnace to obtain ReSe2 film;

[0010] (2) HAuCl4, NaBH4, CTAB and AA are mixed and cysteine ​​solution is added to prepare gold nanoparticle colloid; the gold nanoparticle colloid is dropped onto the ReSe2 film in step (1) to obtain Au-ReSe2 substrate material, which is dried and set aside; the CTAB and AA are mixed to prepare growth solution;

[0011] (3) Phenylalanine solution was added to Au-ReSe2 substrate material, and Au-ReSe2 substrate material loaded with phenylalanine in step (2) was tested using a fully automated laser confocal micro Raman spectrometer.

[0012] To further clarify, the mass ratio of NH4ReO4 to NaCl is 0.9-1.1:3.5-4.5; the mass ratio of the NH4ReO4 and NaCl mixture to the selenium powder is 1:25-40.

[0013] To further clarify, the organic solvent is at least one of cyclohexane, isopropanol, acetone, or ethyl acetate.

[0014] To further explain, in step (2), the cysteine ​​solution is an L-cysteine ​​solution and / or a D-cysteine ​​solution; the gold nanoparticle colloid is L-Au and / or a D-Au.

[0015] Further explanation: In step (2), the concentration of the HAuCl4 solution is 0.1M-0.15M, the concentration of the NaBH4 solution is 80-100mM, the concentration of the CTAB solution is 90-110mM, the concentration of the AA solution is 90-110mM, and the concentration of the cysteine ​​solution is 0.9-1.1mM; the volume ratio of HAuCl4 to NaBH4 is HAuCl4:NaBH4 = 2-3:7-8; the volume ratio of CTAB to AA is CTAB:AA = 10:5-6; and the volume ratio of the gold nanoparticle colloid, the cysteine ​​solution, and the growth solution is 9-11:0.9-1.1:42-52.

[0016] To further explain, in step (3), the phenylalanine solution is at least one of L-Phe solution, D-Phe solution, and DL-Phe solution.

[0017] To further clarify, in step (3), the concentration range of the phenylalanine solution is 10. -3 -10 -7 mol / l.

[0018] To further explain, in step (1), the flow rate of Ar / H2 is 90-110 sccm.

[0019] To further explain, in step (1), the temperature of the first zone of the tubular furnace is 250-350℃, and the temperature of the second zone is 650-750℃.

[0020] To further explain, in step (3), the Au-ReSe2 substrate material loaded with different chiral phenylalanines is tested using a fully automated laser confocal micro Raman spectrometer. The polarization Raman spectroscopy test deflection angle is 60°, and the periodic test is performed from 0 to 360°.

[0021] Compared with existing technologies, the beneficial effects of this invention are: This invention utilizes anisotropic two-dimensional materials, represented by ReSe2, for polarization detection, achieving sensitive detection at specific deflection angles. Simultaneously, chiral AuNPs are used as carriers to adsorb phenylalanine molecules. Through the interaction between enantiomers and specific chiral substances, certain differences can be observed, which not only enhances the Raman signal but also achieves good detection range for low concentrations of Phe (10⁻⁶). -3 -10 -7 Chiral recognition ability (mol / L). Attached Figure Description

[0022] Figure 1 This is an optical microscope image of a ReSe2 monolayer film.

[0023] Figure 2 The rhenium selenide films obtained when the mass ratio of NH4ReO4 to NaCl is 1:1, 1:4, and 1:5 are respectively the rhenium selenide films prepared in Comparative Example 1, Example 2, and Comparative Example 2.

[0024] Figure 3 This is a transmission electron microscope image of gold nanoparticles with a size of 50 nm.

[0025] Figure 4 These are SERS substrate Raman spectra of Au-ReSe2 with different chiral plasmons. From top to bottom, they are SERS substrate Raman spectra of different chiral plasmons in Example 2 (ReSe2-D-AuNPs), Example 1 (ReSe2-L-AuNPs), and Comparative Example 3 (ReSe2).

[0026] Figure 5 These are Raman spectra comparing the isochiral enhancement effects of different chiral phenylalanines. From top to bottom, they are Raman spectra comparing the isochiral enhancement effects of different chiral phenylalanines in Example 1 (ReSe2@L-Au / L-Phe), Example 2 (ReSe2@DAu / LPhe), Example 3 (ReSe2@DAu / DPhe), and Example 4 (ReSe2@LAu / DPhe).

[0027] Figure 6These are Raman spectra of phenylalanine with different chiralities at specific deflection angles. Curves 1 and 2, from top to bottom, represent deflection angles of 180°, 60°, 240°, 0°, 300°, and 120°, respectively; curves 3 and 4, from top to bottom, represent deflection angles of 240°, 0°, 120°, 180°, 300°, and 60°, respectively. Curve 1 represents Example 1, Curve 2 represents Example 4, Curve 3 represents Example 3, and Curve 4 represents the Raman spectra of phenylalanine at specific deflection angles in Example 2. Detailed Implementation

[0028] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0029] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0030] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0031] Example 1 - A method for chiral recognition of phenylalanine

[0032] A. Weigh 2 mg of NH4ReO4 and 8 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 5 mm away from the obtained mixture for growing a monolayer film; weigh 0.2 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain a ReSe2 thin film.

[0033] B. Weigh 200 μL of 0.1 M HAuCl4 solution and add 800 μL of 80 mM NaBH4 solution to form spherical nanoparticles; mix 1.5 mL of 100 mM CTAB solution and 900 μL of 100 mM AA solution as a growth solution to prepare two 2.4 mL portions of the growth solution; take 3 mL of the spherical nanoparticles and add them to one portion of the growth solution, let stand for 20 minutes to form a cubic seed solution; take 40 μL of the cubic seed solution and add it to the other portion of the growth solution, and simultaneously add 3 μL of 1 mM L-cysteine ​​solution to prepare L-Au; drop the prepared L-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0034] C. Add 10 μL of a 10% concentration to the Au-ReSe2 substrate material prepared in step B. -3 The Au-ReSe2 substrate material loaded with L-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a mol / L L-Phe solution. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0035] Example 2 - A method for chiral recognition of phenylalanine

[0036] A. Weigh 2 mg of NH4ReO4 and 8 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 7 mm away from the obtained mixture for growing a monolayer film; weigh 0.3 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain a ReSe2 thin film.

[0037] B. Weigh 300 μL of 0.1 M HAuCl4 solution and add 800 μL of 90 mM NaBH4 solution to form spherical nanoparticles; mix 2 mL of 100 mM CTAB solution and 1000 μL of 100 mM AA solution to prepare two growth solutions, each 3 mL; take 4 mL of the spherical nanoparticles and add them to one of the growth solutions, let stand for 20 minutes to form a cubic seed solution; take 50 μL of the cubic seed solution and add it to the other growth solution, and simultaneously add 3 μL of 1 mM D-cysteine ​​solution to prepare D-Au; drop the prepared D-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0038] C. Add 8 μL of a 10⁻⁶ concentration to the Au-ReSe₂ substrate material prepared in step B. -5 The Au-ReSe2 substrate material loaded with L-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a mol / L L-Phe solution. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0039] Example 3 - A method for chiral recognition of phenylalanine

[0040] A. Weigh 2 mg of NH4ReO4 and 8 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 7 mm away from the obtained mixture for growing a monolayer film; weigh 0.3 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain a ReSe2 thin film.

[0041] B. Weigh 300 μL of 0.1 M HAuCl4 solution and add 800 μL of 90 mM NaBH4 solution to form spherical nanoparticles; mix 2 mL of 100 mM CTAB solution and 1000 μL of 100 mM AA solution to prepare two growth solutions, each 3 mL; take 4 mL of the spherical nanoparticles and add them to one of the growth solutions, let stand for 20 minutes to form a cubic seed solution; take 50 μL of the cubic seed solution and add it to the other growth solution, and simultaneously add 3 μL of 1 mM D-cysteine ​​solution to prepare D-Au; drop the prepared D-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0042] C. Add 8 μL of a 10⁻⁶ concentration to the Au-ReSe₂ substrate material prepared in step B. -5 The Au-ReSe2 substrate material loaded with D-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a D-Phe solution of mol / L. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0043] Example 4 - A method for chiral recognition of phenylalanine

[0044] A. Weigh 2 mg of NH4ReO4 and 8 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 10 mm away from the obtained mixture for growing a monolayer film; weigh 0.4 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 350℃ and the temperature of the second temperature zone to 750℃ to carry out selenization and obtain a ReSe2 thin film.

[0045] B. Weigh 300 μL of 0.15 M HAuCl4 solution and add 800 μL of 100 mM NaBH4 solution to form spherical nanoparticles; mix 2 mL of 100 mM CTAB solution and 1000 μL of 100 mM AA solution to prepare two growth solutions, each 3 mL; take 6 mL of the spherical nanoparticles and add them to one of the growth solutions, let stand for 20 minutes to form a cubic seed solution; take 60 μL of the cubic seed solution and add it to the other growth solution, and simultaneously add 6 μL of 1 mM L-cysteine ​​solution to prepare L-Au; drop the prepared L-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0046] C. Add 12 μL of a 10⁻⁶ concentration to the Au-ReSe₂ substrate material prepared in step B. -7 The Au-ReSe2 substrate material loaded with D-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a D-Phe solution of mol / L. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0047] Comparative Example 1 - A method for chiral recognition of phenylalanine

[0048] The procedure is based on Example 2, except that the mass ratio of NH4ReO4 to NaCl is 1:1.

[0049] A. Weigh 5 mg of NH4ReO4 and 5 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 7 mm away from the obtained mixture for growing a monolayer film; weigh 0.3 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain a ReSe2 thin film.

[0050] B. Weigh 300 μL of 0.1 M HAuCl4 solution and add 800 μL of 90 mM NaBH4 solution to form spherical nanoparticles; mix 2 mL of 100 mM CTAB solution and 1000 μL of 100 mM AA solution to prepare two growth solutions, each 3 mL; take 4 mL of the spherical nanoparticles and add them to one of the growth solutions, let stand for 20 minutes to form a cubic seed solution; take 50 μL of the cubic seed solution and add it to the other growth solution, and simultaneously add 3 μL of 1 mM D-cysteine ​​solution to prepare D-Au; drop the prepared D-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0051] C. Add 8 μL of a 10⁻⁶ concentration to the Au-ReSe₂ substrate material prepared in step B. -5 The Au-ReSe2 substrate material loaded with L-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a mol / L L-Phe solution. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0052] Comparative Example 2 - A method for chiral recognition of phenylalanine

[0053] The procedure is based on Example 2, except that the mass ratio of NH4ReO4 to NaCl is 1:5.

[0054] A. Weigh 1.5 mg of NH4ReO4 and 7.5 mg of NaCl, place them in an agate ball mill jar, and wet-mill with non-polar cyclohexane as solvent for 2 h; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 7 mm away from the obtained mixture for growing a monolayer film; weigh 0.3 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain a ReSe2 thin film.

[0055] B. Weigh 300 μL of 0.1 M HAuCl4 solution and add 800 μL of 90 mM NaBH4 solution to form spherical nanoparticles; mix 2 mL of 100 mM CTAB solution and 1000 μL of 100 mM AA solution to prepare two growth solutions, each 3 mL; take 4 mL of the spherical nanoparticles and add them to one of the growth solutions, let stand for 20 minutes to form a cubic seed solution; take 50 μL of the cubic seed solution and add it to the other growth solution, and simultaneously add 3 μL of 1 mM D-cysteine ​​solution to prepare D-Au; drop the prepared D-Au onto the ReSe2 film in step A to obtain the Au-ReSe2 substrate material.

[0056] C. Add 8 μL of a 10⁻⁶ concentration to the Au-ReSe₂ substrate material prepared in step B. -5 The Au-ReSe2 substrate material loaded with L-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a mol / L L-Phe solution. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0057] Comparative Example 3 - A method for chiral recognition of phenylalanine

[0058] Referring to Example 2, the difference in Comparative Example 3 is that it uses ReSe2 as a base.

[0059] A. Weigh 2 mg of NH4ReO4 and 8 mg of NaCl, place them in an agate ball mill jar, and wet ball mill them for 2 h using non-polar cyclohexane as solvent; then remove the sample from the ball mill jar, centrifuge and dry for 6 h to obtain a mixture of NH4ReO4 and NaCl; place the obtained mixture in the second zone of a dual-temperature zone tube furnace, and place a clean single-layer polished alumina substrate 7 mm away from the obtained mixture for growing a monolayer film; weigh 0.3 g of selenium powder and place it in the first temperature zone of the dual-temperature zone tube furnace, and pass Ar / H2 into the tube furnace at a flow rate of 100 sccm; adjust the temperature of the first temperature zone of the tube furnace to 300℃ and the temperature of the second temperature zone to 700℃ to carry out selenization and obtain the ReSe2 substrate material.

[0060] B. Add 8 μL of a 10⁻⁶ concentration to the ReSe₂ substrate material prepared in step A. -5 The Au-ReSe2 substrate material loaded with D-Phe was tested using a fully automated laser confocal micro Raman spectrometer with a D-Phe solution of mol / L. The polarized Raman spectroscopy test was performed periodically from 0 to 360° with a deflection angle of 60°.

[0061] Raman spectroscopy tests were performed on the above-described embodiments and comparative examples, and the results are as follows:

[0062] Phenylalanine characteristic peak position Raman intensity (au) Example 1 <![CDATA[1600cm -1 、1800cm -1 ]]> 1750、1680 Example 2 <![CDATA[1600cm -1 、1800cm -1 ]]> 720、450 Example 3 <![CDATA[1600cm -1 、1800cm -1 ]]> 1060、810 Example 4 <![CDATA[1600cm -1 、1800cm -1 ]]> 560、300 Comparative Example 1 <![CDATA[1600cm -1 、1800cm -1 ]]> 310、180 Comparative Example 2 <![CDATA[1600cm -1 、1800cm -1 ]]> 450、270 Comparative Example 3 <![CDATA[1600cm -1 、1800cm -1 ]]> 230、120

[0063] The above results indicate that Examples 1-4 of the present invention produce a significant SERS recognition enhancement effect on substrate materials with the same chirality as Phe, and due to the differences arising from the anisotropy of ReSe2. Figure 6 As shown, the SERS enhancement effect of L-Au is significant at a deflection angle of 180°, while the SERS enhancement effect of D-Au is significant at a deflection angle of 240°.

[0064] In conjunction with Example 2, Comparative Example 1, and Comparative Example 2, such as Figure 2 As shown, when the mass ratio of NH4ReO4 to NaCl is 1:1, only a few irregular ReSe2 samples appear on the substrate. With increasing NaCl content, the number of nucleation sites on the substrate increases, and the morphology gradually becomes more regular. When the mass ratio of NH4ReO4 to NaCl is 1:5, a large number of thick ReSe2 samples appear on the substrate due to the excessively fast reaction rate. Optical microscopy results indicate that low NaCl content is insufficient to allow the precursor vapor to react extensively at the bottom of the substrate at 700℃. Therefore, it can be seen that as the NaCl content increases, the reaction rate gradually increases, the number of nucleation sites gradually increases, and the optical contrast of the samples becomes more uniform. The best sample quality is achieved when the mass ratio of NH4ReO4 to NaCl is 1:4.

[0065] Comparative Example 3 shows that, as Figure 4 As shown, the Raman spectrum of the Au-ReSe2 substrate is nearly 7 times stronger than that of the ReSe2 substrate without gold nanoparticles.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for chiral recognition of phenylalanine, characterized in that, Includes the following steps: (1) Take NH4ReO4 and NaCl powder, add organic solvent, ball mill and centrifuge to dry, to obtain a mixture of NH4ReO4 and NaCl; place the mixture in a tube furnace, place a single-layer polished alumina substrate 5-10 mm away from the mixture, and introduce a mixed gas containing Ar and H2 as a carrier gas to heat and react the selenium powder with NH4ReO4 in the tube furnace to obtain a ReSe2 film; (2) HAuCl4, NaBH4, CTAB and AA are mixed and cysteine ​​solution is added to prepare gold nanoparticle colloid; the gold nanoparticle colloid is dropped onto the ReSe2 film in step (1) to obtain Au-ReSe2 substrate material, which is dried and set aside; the CTAB and AA are mixed to prepare growth solution; (3) Phenylalanine solution was dropped into Au-ReSe2 substrate material, and Au-ReSe2 substrate material loaded with phenylalanine in step (2) was tested using a fully automated laser confocal micro Raman spectrometer. The cysteine ​​is an L-cysteine ​​solution or a D-cysteine ​​solution; the gold nanoparticle colloid is a levorotatory gold nanoparticle or a dextrorotatory gold nanoparticle.

2. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The mass ratio of NH4ReO4 to NaCl is 0.9-1.1:3.5-4.5; the mass ratio of the NH4ReO4 and NaCl mixture to the selenium powder is 1:25-40.

3. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The organic solvent is at least one of cyclohexane, isopropanol, acetone or ethyl acetate.

4. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The concentrations of the HAuCl4 solution are 0.1M-0.15M, the NaBH4 solution is 80-100mM, the CTAB solution is 90-110mM, the AA solution is 90-110mM, and the cysteine ​​solution is 0.9-1.1mM; the volume ratio of HAuCl4 to NaBH4 is HAuCl4:NaBH4 = 2-3:7-8; the volume ratio of CTAB to AA is CTAB:AA = 10:5-6; and the volume ratio of the gold nanoparticle colloid, the cysteine ​​solution, and the growth solution is 9-11:0.9-1.1:42-52.

5. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The phenylalanine solution is at least one of L-Phe solution, D-Phe solution, and DL-Phe solution.

6. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The concentration range of the phenylalanine solution is 10. -3 -10 -7 mol / l.

7. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The flow rate of the mixed gas containing Ar and H2 is 90-110 sccm.

8. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The temperature of the first zone of the tubular furnace is 250-350℃, and the temperature of the second zone is 650-750℃.

9. The method for chiral recognition of phenylalanine according to claim 1, characterized in that, The Au-ReSe2 substrate material loaded with different chiral phenylalanines was tested using a fully automated laser confocal micro Raman spectrometer. The polarization Raman spectroscopy test deflection angle was 60°, and the test was performed periodically from 0 to 360°.

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