Neomycin specific detection based on surface plasmon enhanced gold triangle

Abstract

Based on the surface plasmon resonance enhancement of gold triangle, the specific detection of neomycin is involved in the field of analysis and detection. The characteristics of the tip of the gold triangle are easy to gather charges, which can regulate the surface plasmon of silver sol and induce the adsorption orientation of neomycin on the surface of silver sol, causing the displacement of its Raman characteristic peak, realizing the identification and differentiation of its homologues, and achieving the specific SERS detection of neomycin. Under the optimal experimental conditions, the linear detection range of neomycin is 10 ‑5 ~10 ‑10 M, and the relative standard deviation of SERS intensity is less than 10%. The method is simple, accurate and sensitive, and does not require complex operation technology, which meets the requirements of large-scale and rapid analysis and detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of neomycin detection, and particularly to specific detection of neomycin based on gold triangle surface plasmon enhancement. BACKGROUND

[0002] Neomycin (NEO) is listed as a broad-spectrum antibiotic, which is widely used in the treatment of bacterial infections in humans and animals due to its inhibitory effect on both gram-positive and gram-negative bacteria. Neomycin can interfere with protein synthesis in bacteria by binding to the 30s or 50s subunit of ribosomal RNA, resulting in misreading of the genetic code and inhibition of translation. In terms of pathogenicity, NEO has potential neurotoxicity and nephrotoxicity in humans and animals. In recent years, as people's requirements for food safety quality are getting higher and higher, the harm of antibiotics is getting more and more attention. The overuse of antibiotics has caused problems such as bacterial resistance and drug residues in the food chain, which seriously endanger the health of animals and humans and the import and export trade. Therefore, the monitoring of antibiotic residues in food is considered an important public health issue.

[0003] Many instrumental methods have been developed to detect NEO residues, including high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS) or LC-MS / MS, electrochemical method and fluorescence method. Although these methods can obtain accurate and precise analysis results, they usually require precise instruments, well-trained professionals, and a large amount of time and effort, which greatly limits their application range. Surface-enhanced Raman spectroscopy (SERS) is a sensitive, rapid and non-destructive molecular vibrational spectroscopy technique that can provide a unique "fingerprint" of a molecule. Under the irradiation of incident light, the molecules to be measured will be adsorbed on the surface of certain noble metals (gold, silver, copper, etc.) or sol nanoparticles to produce local electric field enhancement or chemical enhancement, thereby greatly enhancing the Raman scattering intensity of the measured substance, and the enhancement factor can reach 10 -4 ~10 -6 , effectively making up for the defects of weak traditional Raman scattering intensity and low sensitivity. SUMMARY

[0004] The present application aims to solve the above-mentioned problems in the prior art, and provides a simple, rapid and reliable SERS (surface-enhanced Raman scattering) detection method for neomycin, which quantitatively analyzes neomycin by using silver nanoparticles and gold triangle nanoparticles as SERS substrates. Under the optimized conditions of the best addition amount and pH, quantitative analysis of neomycin is realized. The linear detection range of neomycin is 10 -5 ~10 -10M, the relative standard deviation of SERS intensity is less than 10%. Silver nano as SERS substrate has the advantages of low cost, controllability, detection efficiency and the like, silver nano is mixed with gold triangle, the magnetic field of silver nano particles is superimposed with the magnetic field of gold triangle nano particles, the gold triangle is easier to gather electric charge due to the sharp end, the plasmon on the surface of silver nano is adjusted, the Raman characteristic peak of neomycin is shifted, the specificity is improved, practical detection application can be carried out in the SERS detection of neomycin. Practical detection popularization application can be carried out in the SERS detection of antibiotics and the like. And the method is simple in operation, high in accuracy and sensitivity, does not need complex operation technology, and can meet the requirements of large quantity and rapid analysis and detection.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] Based on the specific detection of neomycin by gold triangle surface plasmon enhancement, silver nano particle sol is mixed with neomycin sample solution, and then gold triangle nano particle sol is added into the mixed solution to perform surface enhanced Raman detection on neomycin, and other homologous aminoglycoside antibiotics are distinguished according to the movement of the Raman characteristic peak of neomycin.

[0007] The silver nano particle sol is prepared by sodium citrate reduction method.

[0008] The gold triangle nano particle sol is prepared by two-step seed growth method.

[0009] In the present application, the quantitative analysis and detection of the sample solution on the SERS substrate is specifically as follows: with the increase of the concentration of the sample solution, the Raman peak of the sample to be detected at a specific wavelength is gradually enhanced, a standard curve is established by using the relationship between the intensity of the Raman characteristic peak of the sample to be detected and the amount of the sample to be detected, and the sample to be detected is quantitatively analyzed and detected.

[0010] In the present application, the linear detection range of neomycin is 10 -5 ~10 -10 M, the relative standard deviation of SERS intensity is less than 10%.

[0011] The other homologous aminoglycoside antibiotics include netilmicin, amikacin, kanamycin, gentamicin, tobramycin and streptomycin.

[0012] The pH value of the mixed solution of the silver nano particle sol, the neomycin sample solution and the gold triangle nano particle sol is 4-6.

[0013] The excitation wavelength of the surface enhanced Raman detection is 785 nm.

[0014] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0015] The application takes silver nanoparticles and gold triangle nanoparticles as SERS substrates. The SERS substrate not only has excellent SERS Raman enhancement effect, excellent stability and sensitivity. Meanwhile, the SERS substrate has simple preparation process, low cost, high repeatability, excellent detection sensitivity and simple and easy-to-operate detection method. Neomycin is selected as the target molecule, and the Raman enhancement effect of silver sol and gold triangle as the SERS substrate on neomycin is tested by adjusting pH. The experimental results show that the silver sol and the gold triangle as the SERS substrate have excellent Raman enhancement effect. The gold triangle has a sharp tip, which is more likely to gather electric charges, and can control the surface plasmon of the silver sol, so that the Raman characteristic peak of neomycin is shifted, which can distinguish the homologues and improve the specificity. The signal intensity of the sample solution at the characteristic Raman peak has a linear relationship with the concentration, and a simple, rapid, low-cost and specific modification-free quantitative analysis method is established by directly using the SERS characteristic peak of the sample solution. The linear detection range of neomycin is 10 -5 ~10 -10 M, and the relative standard deviation of SERS intensity is less than 10%. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1A is a TEM image of a single silver nanometer size; Figure 1 Fig. 1B is a TEM image of silver sol; Figure 1 Fig. 1C is a TEM image of gold triangle nanometer; Figure 1 Fig. 1D is a TEM image of silver sol and gold triangle nanometer after mixing.

[0017] Figure 2 Fig. 2A is a UV spectrum of gold triangle nanometer before and after purification; Figure 2 Fig. 2B is a UV spectrum of silver nanometer, neomycin and gold triangle nanometer added in sequence.

[0018] Figure 3 Fig. 3A is a SERS spectrum of silver nanometer, neomycin and gold triangle nanometer added in sequence; Figure 3 Fig. 3B is a SERS spectrum of silver nanometer, gold triangle, silver nanometer plus gold triangle substrate.

[0019] Figure 4 Fig. 4 is a SERS spectrum of neomycin and silver sol solution under different volume ratios.

[0020] Figure 5 Fig. 5A is a SERS spectrum of neomycin under different gold triangle nanometer sol addition conditions; Figure 5 Fig. 5B is a SERS spectrum of neomycin under different pH conditions.

[0021] Figure 6 Fig. 6A is a SERS spectrum of neomycin (10-5 SERS spectrum of M); Figure 6 B represents ten parallel measurements of neomycin (10) -5 M) at 761 cm -1 A histogram of SERS peak intensity at the location.

[0022] Figure 7 In Figure A, the SERS spectra of neomycin at different concentrations are shown, where the concentration is 10. -6 M, 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M; Figure 7 In the middle, B is neomycin at 761 cm -1 A graph showing the relationship between SERS intensity and the negative logarithm of concentration at a given location.

[0023] Figure 8 In Figure A, the SERS spectra of different aminoglycoside antibiotic solutions with only silver nanoparticles are shown. From top to bottom, they are tobramycin, kanamycin, gentamicin, neomycin, and streptomycin. Figure 8 The middle image shows the SERS spectra of different aminoglycoside antibiotic solutions with silver nanoparticles and gold triangles. From top to bottom, they are neomycin, netilmicin, gentamicin, tobramycin, amikacin, kanamycin, and streptomycin. Detailed Implementation

[0024] To make the technical problems, technical solutions and beneficial effects of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] This invention includes the following steps:

[0026] 1) Silver nanoparticle sol was prepared by sodium citrate reduction method;

[0027] 2) Preparation of golden triangle nanoparticle sol via a two-step seed growth method;

[0028] 3) Neomycin adsorbs onto the surface of a silver sol. The "golden triangle" mechanism modulates plasmon resonance on the silver sol surface, shifting the Raman characteristic peak of the adsorbed neomycin. Silver nanoparticle sol and neomycin sample solution are mixed in an optimal ratio to agglomerate the silver nanoparticles. Then, the golden triangle nanoparticle sol is added to the mixture to further optimize the amount of golden triangle nanoparticle sol added, further modulating the plasmon resonance on the silver sol surface. Under the optimal golden triangle addition condition, the detection pH is optimized by changing the pH of the mixture. Surface-enhanced Raman spectroscopy (SERS) is performed on neomycin under the optimal addition amount and pH. The shift in the Raman characteristic peak of neomycin allows for the differentiation of homologous aminoglycoside antibiotics.

[0029] 4) The quantitative analysis of the sample solution on the SERS substrate, with the increase of the concentration of the sample solution, the Raman peak of the sample to be tested at a specific wavelength gradually increases, and a standard curve is established by using the relationship between the intensity of the Raman characteristic peak of the sample to be tested and the amount of the sample to be tested, so as to carry out quantitative analysis and detection on the sample to be tested.

[0030] In step 1, the specific method for preparing the silver nanoparticle sol by sodium citrate reduction method is as follows: first, silver nitrate solution is added to a container, and heated to boiling under magnetic stirring, then sodium citrate aqueous solution is added, and heating reflux is continued for 50-60 min, and then the reaction is naturally cooled to room temperature after the reaction is completed. Specifically, the mass percentage concentration of sodium citrate is 0.8%-1.5%, and the volume ratio of sodium citrate to silver nitrate is 30%-50%; the concentration of the silver nitrate solution is 1-3 mmol / L; the reaction temperature is 90-100 ℃, and the stirring speed is 1000-1500 r / min.

[0031] In step 2, the specific method for preparing the gold triangular nanoparticle sol by two-step seed growth method is as follows: tetrachloroauric acid, sodium borohydride and cetyltrimethylammonium chloride (CTAC) are sequentially added to a container to prepare a gold seed solution. The gold seed solution is added to the first growth solution, i.e. CTAC solution, sodium iodide and tetrachloroauric acid solution with different concentrations, and then the mixed solution is added to the second growth solution, i.e. another CTAC solution, sodium iodide and tetrachloroauric acid solution with different concentrations, and then the mixed solution is incubated at room temperature to prepare the gold triangular nanoparticle sol. Specifically, the concentration of tetrachloroauric acid in the first growth solution is 0.05-0.1 M, and the addition amount of tetrachloroauric acid is 30-50 μL; the concentration of sodium iodide is 0.01-0.02 M, and the addition amount of sodium iodide is 10-20 μL; the concentration of cetyltrimethylammonium chloride is 0.05-0.15 M, and the addition amount of cetyltrimethylammonium chloride is 1.5-2 μL. The concentration of tetrachloroauric acid in the second growth solution is 0.05-0.1 M, and the addition amount of tetrachloroauric acid is 400-600 μL; the concentration of sodium iodide is 0.01-0.02 M, and the addition amount of sodium iodide is 200-400 μL; the concentration of cetyltrimethylammonium chloride is 0.3-0.6 M, and the addition amount of cetyltrimethylammonium chloride is 30-50 mL.

[0032] In step 3, the sample solution with different concentrations refers to the sample solution prepared by using water as the solvent; the optimal mixing ratio refers to the optimal mixing ratio of silver nanoparticles and neomycin under the condition that the concentration of the sample solution is 10 -5 M / L; and the optimal addition amount refers to the optimal addition amount of the gold triangular solution under the condition that the concentration of the sample solution is 10 -5The optimal amount of the gold triangle solution is 40 μL to 60 μL in the M / L case. The optimal pH condition is to adjust the pH value of the mixed solution of the silver sol, the gold triangle solution and the sample solution to 4 to 6, wherein the neomycin is adjusted by HNO3.

[0033] The movement of the Raman characteristic peak of the neomycin can be used to distinguish the homologous aminoglycoside antibiotics. The characteristic peak of the aminoglycoside antibiotics under the silver nano substrate appears at 1410 cm -1 and 1020 cm -1 , which indicates that it is difficult to distinguish the homologous aminoglycoside antibiotics by using only the silver nano. After the gold triangle is added, the strongest characteristic peak of all the aminoglycoside antibiotics is at 1451 cm -1 and 763 cm -1 , and the neomycin has a peak at 604 cm -1 more than other aminoglycoside antibiotics, 1587 cm -1 more than amikacin, kanamycin and streptomycin, and 1659 cm -1 more than tobramycin, and thus can be used to distinguish the neomycin from other antibiotics. The other aminoglycoside antibiotics are netilmicin, amikacin, kanamycin, gentamicin, tobramycin and streptomycin.

[0034] The standard curve of the quantitative analysis detection is that, under the optimal experimental condition, the logarithmic value of the series concentration of the sample solution is used as the abscissa, and the peak intensity of the sample solution at the strongest characteristic peak is used as the ordinate to establish the standard curve. The linear detection range of the neomycin is 10 -5 ~ 10 -10 M, and the relative standard deviation of the SERS intensity is less than 10%.

[0035] The following gives specific examples.

[0036] Example 1

[0037] 1. Synthesis of silver sol

[0038] Synthesis of Ag nanoparticles with a size of about 50 ± 10 nm: A 1% (mass fraction) aqueous sodium citrate solution was prepared in advance, and a 1 mmol / L AgNO3 solution was prepared. 100 mL of the prepared AgNO3 solution was taken into a single-mouth round-bottom flask, and a magnetic stirrer was used for stirring. An electric heating mantle was used to heat to a boiling reflux state (the reaction temperature was 100 °C, and the stirring speed was 1200 r / min). 3 mL of the prepared 1% aqueous sodium citrate solution was added, and about 1 min after the addition, the solution changed from colorless to milky white and then to a slightly green opaque liquid. The stirring and heating were continued for 60 min, and then the heating mantle was removed to stop heating. The round-bottom flask was naturally cooled to room temperature, covered with aluminum foil paper to seal and store in the dark.

[0039] The Ag nanoparticles prepared by the chemical reduction method had a size of about 50 ± 10 nm. The size and shape of the core-shell nanoparticles were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) (see FIGS. 1A and 1B). Figure 1 )。 Figure 1 FIG. 1A is a TEM image of a single silver nanometer size A; Figure 1 FIG. 1B is a TEM image of a silver sol B.

[0040] 2. Synthesis of gold triangular nanoparticle sol

[0041] Before synthesizing the gold triangular nanoparticle, gold seed preparation was needed. First, 0.05 M HAuCl4 was added to a 0.1 M CTAC solution, and then 0.01 M freshly prepared NaBH4 was quickly added to the above solution under the condition of 1200 rpm stirring. The obtained solution was Seed@CTAC.

[0042] The following two kinds of growth solutions were prepared: (1) 1.6 mL of the CTAC solution was added to 8 mL of pure water, and then 40 µL of HAuCl4 and 15 µL of NaI were added and mixed uniformly, and the obtained solution was the first growth solution. (2) 500 µL of HAuCl4 solution was added to 40 mL of CTAC, and then 300 µL of NaI was added and mixed uniformly, and the obtained solution was the second growth solution. 40 µL and 400 µL of AA solution were added to the first growth solution and the second growth solution, respectively, and quickly stirred. Finally, 100 µL of Seed@CTAC diluted 10 times was quickly added to the first growth solution, and then 3.2 mL of the obtained solution was quickly added to the second growth solution, and the obtained solution was kept at room temperature for a period of time.

[0043] The embodiment can prepare relatively pure gold triangle nanoparticle sol by purification. 5 mL of 25 wt% CTAC solution is added to the above solution, the obtained solution is kept at room temperature for 16-24 h, the supernatant is absorbed, and the precipitate is re-dispersed in 5 mL of 0.1M CTAC solution to complete the purpose of purification.

[0044] Figure 1 Fig. 3A is a TEM image of gold triangle nanoparticles; Figure 1 Fig. 3D is a TEM image of a mixture of silver sol and gold triangle nanoparticles. Figure 2 Fig. 3A is a UV spectrum of gold triangle nanoparticle sol before and after purification, it can be seen that the peak at 650 nm is higher, indicating that the gold triangle is successfully purified.

[0045] Figure 2 Fig. 3B is a UV spectrum of silver nanoparticles, neomycin and gold triangle nanoparticles added in sequence, the peak at 420 nm decreases after mixing neomycin and silver nanoparticles, indicating that silver nanoparticles are aggregated; after adding gold triangle nanoparticles, a gold nanoparticle wave peak appears at 650 nm, indicating that gold triangle begins to affect silver nanoparticles. Figure 3 Fig. 3A is a SERS spectrum of silver nanoparticles, neomycin and gold triangle nanoparticles added in sequence, it can be seen that the Raman signal changes after adding gold triangle, indicating that gold triangle is more likely to aggregate charges due to its sharp tip, and can regulate the surface plasmon of silver sol, so that the Raman characteristic peak of neomycin is shifted, which can distinguish it from its homologues and improve the specificity of selection. Figure 3 Fig. 3B is a SERS spectrum of silver nanoparticles, gold triangle, silver nanoparticles and gold triangle substrate, there is no signal in silver nanoparticles, gold triangle, silver nanoparticles and gold triangle mixture, indicating that the substrate has no signal, and the measured peak is the Raman characteristic peak of neomycin.

[0046] 3, Optimal amount ratio of neomycin to silver nanoparticles

[0047] The concentration of silver sol and the concentration of neomycin solution are fixed, the volume ratio of silver sol and neomycin solution is adjusted, the surface-enhanced Raman spectrum of neomycin is scanned, and the optimal amount ratio between silver sol and neomycin solution is determined.

[0048] The concentration of silver sol is fixed as the original solution concentration, the concentration of neomycin solution is 10 -5 M, the volume ratio of neomycin to silver sol is adjusted to 3:1, 2:1, 1:1, 1:2 and 1:3, and the SERS spectrum is collected, as shown in Figure 4 It can be seen that when the volume ratio of silver sol to neomycin solution reaches 1:1, the SERS intensity of neomycin reaches the strongest, so the volume ratio of silver sol to neomycin solution is fixed as 1:1 in the subsequent experiment.

[0049] 3, Optimal amount ratio of neomycin to silver nanoparticles

[0050] The fixed silver sol and gold triangular nanoparticle sol were used as the original solution, and the concentration of neomycin solution was 10 -5 M, the fixed amount of silver sol and neomycin solution was 50 μL, the amount of gold triangular nanoparticle sol was adjusted to 25 μL, 50 μL, 75 μL, and 100 μL, and the SERS spectrum was collected, as shown in Fig. 2A. Figure 5 It can be seen that when the amount of gold triangular nanoparticle sol reaches 50 μL, the SERS intensity of neomycin reaches the strongest, so the amount of gold triangular nanoparticle sol in the subsequent experiment is 50 μL.

[0051] 4. Optimal pH of silver sol and neomycin solution

[0052] The amount of gold triangular nanoparticle sol was fixed at 50 μL, and the pH of the mixed solution of gold triangular nanoparticle sol, silver sol, and neomycin solution was adjusted to 3, 4, 5, 6, and 7, respectively, and the surface-enhanced Raman spectrum of neomycin was scanned to determine the optimal pH.

[0053] Figure 5 Fig. 2B is the SERS spectrum of neomycin measured under different pH conditions. It can be seen from the figure that when pH = 5, the intensity of the surface-enhanced Raman signal peak of neomycin is the strongest, so the optimal pH value of the detection system of neomycin is 5.

[0054] 5. Uniformity of SERS substrate of neomycin

[0055] The gold triangular nanoparticle sol, silver sol, and neomycin solution with a concentration of 10 -5 M were taken, the amount of gold triangular nanoparticle sol was fixed at 50 μL, the pH was adjusted to 5, and the SERS spectrum was randomly collected ten times on the substrate with an excitation wavelength of 785 nm. The SERS peak intensity of neomycin measured ten times in parallel was compared to determine the uniformity of the SERS substrate.

[0056] Figure 6 Fig. 3A is the SERS spectrum of tobramycin measured ten times in parallel. Figure 6 Fig. 3B is a column chart of the SERS peak intensity of neomycin at 761 cm -1 It can be seen that the relative standard deviation (RSD) calculated from the SERS characteristic peak intensity of 10 parallel samples is 3.98 %, which is less than 10 %, indicating that the uniformity of the SERS substrate is good and can be applied to the quantitative analysis of surface-enhanced Raman of neomycin.

[0057] 6. SERS detection of neomycin

[0058] The gold triangular nanoparticle sol, silver sol, and neomycin solution with a concentration of 10 -5The SERS spectra of neomycin with different concentrations were measured by using the gold triangle nanoparticle sol and 50 μL of the fixed gold triangle nanoparticle sol, adjusting the pH value to 5, and collecting the SERS spectra under the excitation of 785 nm excitation light.

[0059] Figure 7 Fig. 4 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -6 Fig. 5 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -7 Fig. 6 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -8 Fig. 7 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -9 Fig. 8 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -10 Fig. 9 shows the SERS spectra of neomycin with different concentrations, wherein the concentrations from top to bottom are 10

[0060] Figure 7 Fig. 10 shows the standard curve of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -6 Fig. 11 shows the standard curve of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -10 Fig. 12 shows the standard curve of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 -1 Fig. 13 shows the standard curve of neomycin with different concentrations, wherein the concentrations from top to bottom are 10 2 Fig. 14 shows the standard curve of neomycin with different concentrations, wherein the concentrations from top to bottom are 10

[0061] 7. Selectivity of gold triangle nanoparticle sol and silver nanoparticle sol to aminoglycoside antibiotics

[0062] Fig. 15 shows the SERS spectra of tobramycin, kanamycin, gentamicin, neomycin and streptomycin with a concentration of 10 -5 Fig. 16 shows the SERS spectra of tobramycin, kanamycin, gentamicin, neomycin and streptomycin with a concentration of 10

[0063] Fig. 17 shows the SERS spectra of netilmicin, amikacin, kanamycin, gentamicin, tobramycin, streptomycin and neomycin with a concentration of 10 -5 Fig. 18 shows the SERS spectra of netilmicin, amikacin, kanamycin, gentamicin, tobramycin, streptomycin and neomycin with a concentration of 10

[0064] Figure 8Figure A shows the SERS spectra of different aminoglycoside antibiotic solutions with only silver nanoparticles added. From top to bottom, they are tobramycin, kanamycin, gentamicin, neomycin, and streptomycin. It can be seen that tobramycin, gentamicin, and neomycin all have Raman signals at the main peaks of 1410 cm and 1020 cm, and other smaller peaks also have the same Raman signals. This indicates that it is difficult to distinguish similar aminoglycoside antibiotics using only silver nanoparticles. Figure 8 Image B shows the SERS spectra of different aminoglycoside antibiotic solutions with silver nanoparticles and the antibiotics themselves. From top to bottom, they are neomycin, netilmicin, gentamicin, tobramycin, amikacin, kanamycin, and streptomycin. As can be seen from the image, the Raman peak positions of the other aminoglycoside antibiotics are not the same as those of neomycin; gentamicin and netilmicin have a Raman peak position 1687 cm⁻¹ higher than that of neomycin. -1 At the peak, neomycin was 1587 cm⁻¹ higher than that of amikacin, kanamycin, and streptomycin. -1 At the peak, tobramycin had a 1659 cm⁻¹ higher peak than neomycin. -1 At the peak, neomycin was 604 cm⁻¹ higher than other antibiotics. -1 The peak at the gold nanoparticle sol can be used to distinguish neomycin from other aminoglycoside antibiotics. This indicates that the Raman peaks of aminoglycoside antibiotics changed after the addition of the gold nanoparticle sol, and the peak shapes of antibiotics in the same class also changed. Therefore, under acidic conditions (pH=4-6), silver nanoparticle sol and gold nanoparticle sol as SERS substrate can distinguish netilmicin, amikacin, kanamycin, gentamicin, tobramycin, streptomycin, and neomycin. This system can distinguish aminoglycoside antibiotics in the same class.

[0065] This invention mixes silver nanoparticles with gold triangles, superimposing the magnetic fields of the silver nanoparticles and the gold triangles to increase the Raman intensity of neomycin detection. Simultaneously, the unique structure of the gold triangles modulates the plasmons on the surface of the silver sol, shifting the Raman characteristic peak of neomycin and enabling quantitative analysis. Quantitative analysis of neomycin is achieved by optimizing the mixing ratio, dosage, and pH. The linear detection range for neomycin is 10⁻⁶. -5 ~10 -10 The relative standard deviation of the SERS intensity (M) is less than 10%. Silver sol, as a SERS substrate, has advantages such as low cost, controllability, and high detection efficiency. The golden triangle, due to its pointed shape, is more likely to accumulate charges, modulate the plasmons on the surface of the silver sol, change the Raman signal of the groups, shift the Raman signal peak, and improve selectivity. Moreover, this method is simple to operate, accurate, and sensitive, does not require complex operating techniques, and can meet the requirements of large-scale and rapid analysis and detection.

Claims

1. A neomycin specific detection method based on gold triangle surface plasmon resonance enhancement, characterized in that: The silver nanoparticle sol is mixed with a neomycin sample solution, and then the gold triangular nanoparticle sol is added to the mixture, and HNO3 is used to adjust the pH of the mixture to 4-6, so as to perform surface enhanced Raman detection on the neomycin, and according to the movement of the Raman characteristic peaks of the neomycin, other homologous aminoglycoside antibiotics are distinguished; wherein the sample solution refers to a sample solution prepared by using water as a solvent, and the concentration of the sample solution is 10 -5 Under the condition of M / L, the volume ratio of the silver nanoparticle sol to the neomycin sample solution is 1:1, and the gold triangular nanoparticle sol is 40 μL-60 μL.

2. The method for neomycin specific detection based on gold triangle surface plasmon enhancement according to claim 1, characterized in that: The silver nanoparticle sol is prepared by a sodium citrate reduction method.

3. The method for neomycin specific detection based on gold triangle surface plasmon enhancement according to claim 1, characterized in that: The gold triangular nanoparticle sol is prepared by a two-step seed growth method.

4. The method for neomycin specific detection based on gold triangle surface plasmon resonance enhancement according to claim 1, characterized in that: The quantitative analysis and detection of the sample solution on the SERS substrate is specifically as follows: with the increase of the concentration of the sample solution, the Raman peak of the sample to be detected at a specific wavelength gradually strengthens, a standard curve is established by using the relationship between the intensity of the Raman characteristic peak of the sample to be detected and the quantity of the sample to be detected, and the sample to be detected is subjected to quantitative analysis and detection.

5. The method for neomycin specific detection based on gold triangle surface plasmon enhancement according to claim 1, characterized in that: The linear detection range of neomycin is 10 -5 ~10 -10 M, the relative standard deviation of SERS intensity is less than 10%.

6. The method for neomycin specific detection based on gold triangle surface plasmon enhancement according to claim 1, characterized in that: The other homologous aminoglycoside antibiotics include netilmicin, amikacin, kanamycin, gentamicin, tobramycin and streptomycin.

7. The method for neomycin specific detection based on gold triangle surface plasmon enhancement according to claim 1, characterized in that: The excitation wavelength of the surface-enhanced Raman detection is 785 nm.

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