Preparation of TiO2 core Ag satellite hybrid superstructure and SERS detection application of sisomicin

Abstract

A kind of TiO2 core Ag satellite hybrid super nanostructure preparation and sisomicin SERS detection application, it is related to the field of analysis and detection, first TiO2 microsphere surface modification, by electrostatic adsorption Ag nanoparticles, synthesis a kind of TiO2 core Ag satellite hybrid super nanostructure, can be used as SERS substrate detection sisomicin, by charge transfer mechanism between core and satellite, greatly improve the detection sensitivity of sisomicin.Under the optimal experimental conditions, the linear detection range of sisomicin is 10 ‑5 ~10 ‑11 M, the detection limit is 7.12× 10 ‑12 M, the relative standard deviation of SERS intensity is less than 10%;The method is simple, accurate and high sensitivity, without complex operation technology, meet the requirements of large quantities and rapid analysis and detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of analytical detection, in particular to a TiO2 core Ag satellite hybrid super nanostructure preparation and sisomicin SERS detection application. BACKGROUND

[0002] Sisomicin is an important water-soluble aminoglycoside antibiotic, which is clinically used for the treatment of local or systemic infections caused by gram-negative bacteria. However, sisomicin can cause strong ototoxicity and nephrotoxicity. Improper use can cause allergic reactions and drug resistance of some pathogens. Therefore, it is crucial to monitor the dosage of sisomicin to ensure its therapeutic effect while minimizing side effects.

[0003] Currently, there are limited methods for detecting sisomicin, and most of the detectable methods are high-performance liquid chromatography (HPLC), generally equipped with ultraviolet-visible light, fluorescence, resonance Rayleigh scattering, etc. Because it lacks a chromophore, sisomicin must be treated with a derivatization reagent (1-fluoro-2,4-dinitrobenzene or o-phthalaldehyde) for these research methods. In addition, byproducts are inevitably produced during the derivatization process. For resonance Rayleigh scattering and evaporation light scattering detectors, their sensitivity and selectivity are not satisfactory. Therefore, there is an urgent need to establish a convenient and sensitive sisomicin detection technology. 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 sisomicin, which quantitatively analyzes sisomicin by using TiO2 core Ag satellite hybrid super nanostructure as a SERS substrate. Under the conditions of optimizing the binding amount ratio, the best detection time, and the pH, quantitative analysis of sisomicin is achieved. The linear detection range of sisomicin is 10 -5 ~10 -11 M, the detection limit is 7.12 x 10 -12 M, and the relative standard deviation of SERS intensity is less than 10%. The TiO2 core Ag satellite hybrid super nanostructure as a SERS substrate has the advantages of simple operation, high accuracy and sensitivity, and does not require complex operation techniques, and can be widely applied in the practical detection of SERS detection of antibiotics and the like.

[0005] To achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0006] A sisomicin SERS detection application of a TiO2 core Ag satellite hybrid super nanostructure, comprising the following steps:

[0007] 1) Preparation of silver nanoparticle sol;

[0008] 2) amino modification of TiO2 nano;

[0009] 3) mixing and stirring of the amino modified TiO2 and silver nanoparticle sol to obtain TiO2 core Ag satellite hybrid super nano structure, which is used as SERS substrate;

[0010] 4) mixing of sisomicin sample solution and SERS substrate to detect sisomicin by surface enhanced Raman.

[0011] In step 1), the silver nanoparticle sol is prepared by sodium citrate reduction method.

[0012] In step 2), TiO2 nano is dispersed in water, and then ammonia and aminopropyl triethoxysilane are added for amino modification under water bath stirring.

[0013] In step 4), the pH value of the mixed solution of sisomicin sample solution and SERS substrate is 3-5.

[0014] In step 4), the detection is performed within 0.5 min after mixing.

[0015] In step 4), under the optimal excitation wavelength, the Raman peak of the sample to be detected at a specific wavelength gradually increases with the increase of the concentration of the sample solution, and 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, so as to quantitatively analyze and detect the sample to be detected.

[0016] The optimal excitation wavelength refers to 785 nm excitation wavelength.

[0017] In the present application, the Raman peak of sisomicin at a specific wavelength refers to the characteristic Raman peak of sisomicin at 932 cm -1 .

[0018] In the present application, the linear detection range of sisomicin is 10 -5 ~10 -11 M, and the detection limit is 7.12×10 -12 M.

[0019] The relative standard deviation of SERS intensity of the present application is less than 10%.

[0020] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0021] The application takes TiO2 core Ag satellite prepared by electrostatic adsorption as a SERS substrate. The SERS substrate has excellent SERS Raman enhancement effect and excellent sensitivity. Meanwhile, the SERS substrate has simple preparation process, low cost, high repeatability, excellent detection sensitivity and simple and easy-to-operate detection method. Xithromycin is selected as a target molecule, and the Raman enhancement effect of the TiO2 core Ag satellite nanoparticle as a SERS substrate on xithromycin is tested by adjusting parameters such as pH. The experimental results show that the TiO2 core Ag satellite as a SERS substrate has excellent Raman enhancement effect. The signal intensity of the sample solution at the characteristic Raman peak has a linear relationship with the concentration, and a simple, rapid, specific modification-free and direct quantitative analysis method of the sample solution by using the SERS characteristic peak is established. The linear detection range of xithromycin in the application is 10 -5 ~10 -11 M, the detection limit is 7.12*10 -12 M, and the relative standard deviation of the SERS intensity is less than 10%. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a SEM diagram of the TiO2 core Ag satellite.

[0023] Figure 2 In the medium A, it is the SERS spectrum of the TiO2 core Ag satellite and xithromycin solution under different volume ratios; Figure 2 In the medium B, it is the SERS spectrum of xithromycin measured under different pH conditions.

[0024] Figure 3 It is the SERS spectrum of the TiO2 core Ag satellite and xithromycin solution under different mixing time conditions.

[0025] Figure 4 In the medium A, it is the SERS spectrum of xithromycin (10 -5 M) measured ten times in parallel; Figure 4 In the medium B, it is the column chart of the SERS peak intensity of xithromycin (10 -5 M) at 932 cm -1 .

[0026] Figure 5 In the medium A, it is the SERS spectrum of xithromycin with different concentrations, wherein the concentrations of a to g from top to bottom are (a) 10 -5 M (b) 10 -6 M (c) 10 -7 M (d) 10 -8 M (e) 10 -9 M (f) 10 -10 M (g) 10 -11M; Figure 5 The SERS intensity of sisomicin at 932 cm -1 The figure of the SERS intensity of sisomicin at 932 cm

[0027] Figure 6 The SERS spectra of different aminoglycoside antibiotic solutions, wherein, from top to bottom a→h are (a) sisomicin (b) neomycin (c) tobramycin (d) streptomycin (e) gentamicin (f) kanamycin (g) netilmicin (h) araki micin. DETAILED DESCRIPTION

[0028] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear, specific, the following will be combined with the drawings and examples, and the present application will be further described in detail.

[0029] The present application comprises the following steps:

[0030] 1) The silver nanoparticle sol (silver sol) is prepared by sodium citrate reduction method;

[0031] 2) The TiO2 core Ag satellite hybrid super nanostructure is prepared;

[0032] 3) The optimal sample detection condition is determined. Under the optimal excitation wavelength, the sample solution and the SERS substrate are mixed in the optimal combination amount ratio, the mixing time of the sample solution and the SERS substrate is optimized, the pH condition of the detection is optimized, and the optimal sample detection condition is determined.

[0033] 4) The quantitative analysis and detection 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 detected at a specific wavelength is gradually enhanced, and the 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. The sample to be detected is quantitatively analyzed and detected.

[0034] In step 1), the AgNO3 solution is taken in a flask, stirred and heated to boiling reflux state, sodium citrate is added, the solution becomes opaque liquid with green color, heating and refluxing is continued for 50-60 min, after stopping heating, natural cooling to room temperature, and sealed and stored in dark. The mass percentage concentration of sodium citrate is 0.8%-1.5%, 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 ℃.

[0035] In step 2, the TiO2 is dispersed in ultrapure water, and stirred in a water bath for 5-6 min. Ammonia and aminopropyltriethoxysilane are added, and the stirring is continued in the water bath. After cooling to room temperature, the mixture is centrifuged and ultrasonically treated for 20-30 min, and washed with deionized water three times. The amino-modified TiO2 is mixed with the silver sol, and stirred for 2-3 h to obtain the TiO2 core Ag satellite. The amount of TiO2 is 0.8-1 g, the amount of ultrapure water is 800-1000 ml, the amount of ammonia is 25% by mass and 0.25-0.32 ml by volume, and the amount of aminopropyltriethoxysilane is 0.8-1 ml.

[0036] In step 2, the volume ratio of the silver sol to the TiO2 solution is 25:1.

[0037] In step 3, the optimal combination amount ratio is the volume ratio of the TiO2 core Ag satellite to the sample solution, which is 1:0.5, under the condition that the concentration of the TiO2 core Ag satellite is the same as the concentration of the sample solution, and the concentration of the sample solution is 10 -5 M. The optimal pH condition is that the pH of the mixed solution of the TiO2 core Ag satellite and the sample solution is adjusted to 3-5, and the pH is adjusted by HNO3. The sample solution refers to a sample solution prepared by using water as a solvent. The optimal excitation wavelength refers to an excitation wavelength of 785 nm. The optimal detection time refers to a detection time within 0.5 min after all the substances are mixed.

[0038] In step 4, the Raman peak of sisomicin at a specific wavelength refers to a characteristic Raman peak of sisomicin at 932 cm -1 . The standard curve refers to a standard curve established by using the logarithmic values of the concentrations of the sample solution as the abscissa and the peak intensities of the sample solution at the strongest characteristic peak as the ordinate under the optimal experimental conditions. The linear detection range of sisomicin is 10 -5 ~10 -11 M, the detection limit is 7.12×10 -12 M, and the relative standard deviation of the SERS intensity is less than 10%.

[0039] The following gives specific examples.

[0040] 1. Synthesis of TiO2 core Ag satellite

[0041] Synthesizing Ag nanoparticles with a particle size of approximately 50 ± 10 nm: Prepare a 1% (w / w) sodium citrate aqueous solution and a 1 mmol / L AgNO3 solution. Take 100 mL of the prepared AgNO3 solution and place it in a single-necked round-bottom flask. Stir with a magnetic stirrer and heat to boiling under a heating mantle (reaction temperature 90–100 °C, stirring speed 1000–1500 r / min). Add 3 mL of the pre-prepared 1% sodium citrate aqueous solution. After about 1 minute, the solution changes from colorless to milky white, then to a slightly greenish opaque liquid. Continue stirring and heating until gently boiling for 50–60 minutes. Then remove the heating mantle and stop heating. Allow to cool naturally to room temperature, then cover the round-bottom flask with aluminum foil and seal it to protect it from light.

[0042] To modify TiO2, 0.8 g of TiO2 nanoparticles were dispersed in 800 ml of ultrapure water and stirred in a water bath at 80 °C for 5–6 min. Then, 0.25 ml of 25% ammonia and 0.8 ml of aminopropyltriethoxysilane were added, and the mixture was stirred thoroughly in the water bath for another 6–7 h. After cooling to room temperature, the mixture was centrifuged and sonicated for 30 min, then washed three times with deionized water. The amino-modified TiO2 was then mixed with silver sol and stirred for 2–3 h to obtain the TiO2-core Ag satellite.

[0043] The prepared TiO2 core Ag satellites had a particle size of approximately 200 ± 10 nm. The particle size and shape of the core-shell nanoparticles were characterized by scanning electron microscopy (SEM) (see [link to SEM]). Figure 1 ).

[0044] 2. Optimal ratio of TiO2 core Ag satellite to Sisomistar solution

[0045] The concentration of the TiO2 core Ag satellite was fixed at the stock solution concentration, and the concentration of the sisomicin solution was 10. -5 M. Adjust the volume ratio of TiO2 core Ag satellite and Sisomia solution to 1:0.25, 1:0.5, 1:0.75, 1:1, and 1:1.25, and collect SERS spectra. See [link to relevant data]. Figure 2 As shown in Figure A, when the volume ratio of the TiO2 core Ag satellite to the Sisomi star solution reaches 1:0.5, the SERS intensity of Sisomi star reaches its strongest. Therefore, in subsequent experiments, the volume ratio of the TiO2 core Ag satellite to the Sisomi star solution was fixed at 1:0.5.

[0046] 3. Optimal detection time for TiO2 core Ag satellites and Sisomi star

[0047] The concentration of the TiO2 core Ag satellite was fixed at the stock solution concentration, and the concentration of the sisomicin solution was 10. -5M, the mixing time of TiO2 core Ag satellite and sisomicin solution was adjusted to 0.5 min, 2.5 min, 4.5 min, 6.5 min, 8.5 min, 10.5 min. The surface enhanced Raman spectrum of sisomicin was scanned to determine the optimal mixing time. See Figure 3 It can be seen that when the mixing time of TiO2 core Ag satellite and sisomicin is 0.5 min, the SERS intensity of sisomicin reaches the strongest.

[0048] 4、The optimal pH of TiO2 core Ag satellite and sisomicin solution

[0049] The volume ratio of TiO2 core Ag satellite and sisomicin solution was fixed at 1:0.5, and the pH of the mixed solution of TiO2 core Ag satellite and sisomicin solution was adjusted to 3, 5, 7, 9, 11, respectively. The surface enhanced Raman spectrum of sisomicin was scanned to determine the optimal pH.

[0050] Figure 2 Fig. B is the SERS spectrum of sisomicin 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 sisomicin is the strongest, so the optimal pH value of the detection system of sisomicin is 5.

[0051] 5、The uniformity of the SERS substrate of sisomicin

[0052] Take TiO2 core Ag satellite and sisomicin solution with a concentration of 10 -5 M, fix the volume ratio to 1:0.5, adjust the pH to 5, and mix for 0.5 min. Randomly collect ten SERS spectra on the substrate with an excitation wavelength of 785 nm. Compare the SERS peak intensity of sisomicin measured ten times in parallel to determine the uniformity of the SERS substrate.

[0053] Figure 4 Fig. A is the SERS spectrum of sisomicin measured ten times in parallel. Figure 4 Fig. B is a histogram of the SERS peak intensity of sisomicin at 932 cm -1 It can be seen that the relative standard deviation (RSD) calculated from the SERS characteristic peak intensity of the 10 parallel samples is 6.49% at 932 cm -1 , which is less than 10%, indicating that the uniformity of the SERS substrate is good and can be applied to the quantitative analysis of the surface enhanced Raman of sisomicin.

[0054] 6、The SERS detection of sisomicin

[0055] The TiO2 core Ag satellite was taken with different concentrations of sisomicin solution, the volume ratio was fixed at 1:0.5, the pH was controlled at 5, the mixing time was 0.5 min, and the SERS spectrum was collected under 785 nm excitation light wavelength excitation to measure the SERS spectrum of sisomicin with different concentrations.

[0056] Figure 5 Fig. 4 is a SERS spectrum of sisomicin with different concentrations, wherein the concentrations from top to bottom a→g are 10 -5 M, 10 -6 M, 10 -7 M, 10 -8 M, 10 -9 M, 10 -10 M, 10 -11 M, it can be seen that with the increase of concentration, the surface enhanced Raman peak intensity of sisomicin is stronger.

[0057] Figure 5 Fig. 5 is a standard curve established after detecting sisomicin with different concentrations of standard solution, wherein the concentrations from top to bottom a→g are 10 -5 ~10 -11 M, the intensity of the 932 cm -1 characteristic peak of sisomicin has a positive correlation with the negative logarithm of the concentration of sisomicin (y = 1559.5 x + 19804), R 2 = 0.9945, and the detection limit (LOD) is 7.12 × 10 -12 M.

[0058] 7. Selectivity of TiO2 core Ag satellite to sisomicin, neomycin, tobramycin, streptomycin, gentamicin, kanamycin, netilmicin, and araki micin

[0059] The TiO2 core Ag satellite was taken with sisomicin, neomycin, tobramycin, streptomycin, gentamicin, kanamycin, netilmicin, and araki micin with a concentration of 10 -5 M, the volume ratio was fixed at 0.6-0.7, the pH value was adjusted to 4-6, and the surface enhanced Raman spectrum of sisomicin, neomycin, tobramycin, streptomycin, gentamicin, kanamycin, netilmicin, and araki micin was obtained with 785 nm excitation wavelength.

[0060] Figure 6SERS spectra of different kinds of aminoglycoside antibiotics sisomicin, neomycin, tobramycin, streptomycin, gentamicin, kanamycin, netilmicin, and araki micin solution, wherein, from top to bottom, from a to h, (a) sisomicin, (b) neomycin, (c) tobramycin, (d) streptomycin, (e) gentamicin, (f) kanamycin, (g) netilmicin, and (h) araki micin, as can be seen from the figure, under acidic conditions, the eight kinds of antibiotics can be divided into three categories according to the peak shape, which are araki micin, streptomycin, gentamicin, kanamycin, netilmicin, sisomicin, neomycin, and tobramycin, araki micin does not show characteristic peaks, for streptomycin, gentamicin, kanamycin, and netilmicin, among them, the peaks of streptomycin and gentamicin star disappear at 932 cm -1 , the peaks of kanamycin and netilmicin shift at 785 cm -1 , 932 cm -1 , and 1396 cm -1 , and for sisomicin, neomycin, and tobramycin, the peak intensity at 1089 cm -1 is the strongest, and the peaks of neomycin and tobramycin shift at 785 cm -1 . Therefore, under acidic conditions (pH=5), TiO2 core Ag satellite as a SERS substrate can distinguish sisomicin, neomycin, tobramycin, streptomycin, gentamicin, kanamycin, netilmicin, and araki micin.

[0061] The application uses TiO2 core Ag satellite nanoparticles as a SERS substrate, adsorbs sisomicin on the SERS enhanced region of the TiO2 core Ag satellite nanoparticle aggregates through electrostatic interaction, enhances and amplifies the SERS signal of sisomicin, and performs quantitative analysis on sisomicin. Under the conditions of optimizing the binding amount ratio and pH, quantitative analysis of sisomicin is realized. The linear detection range of sisomicin is 10 -5 ~10 -11 M, the detection limit is 7.12 × 10 -12 M, and the relative standard deviation of SERS intensity is less than 10%. TiO2 core Ag satellite as a SERS substrate has the advantages of low cost, controllability, high detection efficiency, etc., and can be applied to practical detection in the field of SERS detection of antibiotics, etc. Moreover, the method is simple to operate, accurate and sensitive, does not require complex operation technology, and can meet the requirements of large-scale and rapid analysis and detection.

Claims

1. A sisomicyn SERS detection application of TiO2 core Ag satellite hybrid super- nanostructure, characterized in that, The method comprises the following steps: 1) preparing silver nanoparticle sol; 2) amino-modifying TiO2 nanoparticles: dispersing 0.8-1 g TiO2 nanoparticles in 800-1000 ml ultrapure water, water-bath stirring for 5-6 min, adding 0.25-0.32 ml 25% ammonia water and 0.8-1 ml aminopropyl triethoxysilane, continuing water-bath stirring and fully stirring, cooling to room temperature, centrifuging and ultrasonicating for 20-30 min, and washing with deionized water for three times; 3) mixing and stirring the amino-modified TiO2 and silver nanoparticle sol for 2-3 h to obtain TiO2 core Ag satellite hybrid super nanostructure as a SERS substrate; the volume ratio of the silver nanoparticle sol to the amino-modified TiO2 solution is 25:1; 4) mixing the sisomicin sample solution with the SERS substrate to perform surface-enhanced Raman detection of sisomicin, wherein the optimal combination amount ratio is that the concentration of the TiO2 core Ag satellite as the synthesis stock solution is controlled, and the concentration of the sample solution is 10 -5 The volume ratio of the TiO2 core Ag satellite to the sample solution is 1:0.5 in the case of M; the optimal pH condition is that the pH value of the mixed solution of the TiO2 core Ag satellite and the sample solution is adjusted to 3-5; the sample solution refers to a sample solution prepared by using water as a solvent; the optimal excitation wavelength refers to a 785 nm excitation wavelength; and the optimal detection time refers to that detection is performed within 0.5 min after all substances are mixed.

2. The SERS detection application of sisomicyn of a TiO2 core Ag satellite hybrid super-nanostructure according to claim 1, characterized in that: In step 1), the silver nanoparticle sol is prepared by sodium citrate reduction method.

3. The SERS detection application of sisomicyn of a TiO2 core Ag satellite hybrid super-nanostructure according to claim 1, characterized in that: In step 4), under the optimal excitation wavelength, with the increase of the sample solution concentration, 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.

4. The SERS detection application of sisomicyn of a TiO2 core Ag satellite hybrid super-nanostructure according to claim 3, characterized in that: The Raman peak of sisomicin at a particular wavelength refers to the characteristic Raman peak of sisomicin at 932 cm -1 .

5. A sisomicyn SERS detection application of TiO2 core Ag satellite hybrid super- nanostructure according to claim 1, characterized in that: The linear detection range of sisomicin was 10 -5 ~10 -11 M, the detection limit was 7.12 x 10 -12 M.

6. A sisomicyn SERS detection application of a TiO2 core Ag satellite hybrid super-nanostructure according to claim 1, characterized in that: The relative standard deviation of SERS intensity is less than 10%.

Images