A green preparation method for composite SERS substrate for industrial dye detection

Abstract

A green preparation method of a composite SERS substrate for industrial dye detection, which belongs to the technical field of inorganic nanomaterial preparation. It aims to solve the problems of strong fluorescence, poor biocompatibility, high price, and easy oxidation of noble metal SERS substrates for detecting industrial dyes. Method: First, mix Ti3C2T x Mxene powder with ferric chloride solution to prepare multi-layered Ti3C2T x Mxene; Second, mix multi-layered Ti3C2T x Mxene with chloroauric acid solution to prepare accordion-like Ti3C2T x Mxene, and after dispersion, drop it onto a silicon wafer and let it dry naturally. The present invention prepares a gold nanoparticle-modified Ti3C2T x Mxene composite SERS substrate material for industrial dye detection by a green and simple method, avoiding the use of fluorides and maintaining excellent SERS performance at the same time. The product prepared by the present invention is used as an inorganic nanomaterial.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic nano material preparation, and particularly relates to a green preparation method of a composite SERS substrate for industrial dye detection. Background Art

[0002] With the large-scale use of industrial dyes such as basic violet and basic orange, water environment safety and human health are threatened. For example, basic orange II is a type of industrial azo dye commonly used for dyeing textiles and wood products. Its preparation process and finished products have certain pathogenicity, toxicity, carcinogenicity and teratogenicity to the human body. Due to its low price and good dyeing properties, illegal vendors illegally use it for coloring peppers, bean curd and seafood, which seriously endangers the health of consumers. At present, the commonly used methods for detecting basic orange II include oscillographic polarography, thin layer chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. These methods inevitably have problems such as poor anti-interference, large errors, low detection sensitivity, and the need for sample pretreatment. Surface enhanced Raman spectroscopy (SERS) technology can achieve ultra-sensitive non-destructive detection at the single molecule level, which is an ideal method for detecting industrial dye basic orange II. However, the gold and silver substrates currently used for detection have the disadvantages of strong fluorescence, poor biocompatibility, high price and easy oxidation. Two-dimensional material Ti3C2T x With its large specific surface area and adjustable surface, it can effectively solve these problems as a substrate for loading precious metals, reduce costs, stabilize performance while maintaining excellent SERS performance, and is an ideal substrate material for detecting basic orange II. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of strong fluorescence, poor biocompatibility, high price and easy oxidation of the existing noble metal SERS substrates for detecting industrial dyes, and to provide a green preparation method of a composite SERS substrate for industrial dye detection.

[0004] A green preparation method of a composite SERS substrate for industrial dye detection is achieved by the following steps:

[0005] 1. Preparation of Ti3C2T x The Mxene powder is then mixed with the ferric chloride solution by magnetic stirring, and after washing and drying, a multilayer Ti3C2T x Mxene;

[0006] 2. The above multilayer Ti3C2T x Mxene was mixed with chloroauric acid solution by magnetic stirring, and after washing and drying, accordion-shaped Ti3C2T xMxene, then placed in deionized water for ultrasonic dispersion, and then dropped onto a silicon wafer for natural drying to obtain a composite SERS substrate for industrial dye detection, thereby completing the green preparation method.

[0007] The present invention adopts a green and simple method to prepare a composite SERS substrate material for industrial dye detection, avoiding the use of fluoride; the present invention uses Lewis acid salt NiCl2·6H2O to remove the Al atomic layer of Ti3AlC2 phase, and uses ferric chloride to remove the generated nickel element to prepare accordion-shaped Ti3C2T x Mxene material, reuse Ti3C2T x The reductive property of Mxene itself reduced chloroauric acid and successfully prepared gold nanoparticle-modified Ti3C2T3 for industrial dye detection. x The Mxene composite SERS substrate material avoids the problems of existing precious metal SERS substrates, such as strong fluorescence, poor biocompatibility, high price and easy oxidation.

[0008] The present invention solves the existing problems while maintaining excellent SERS performance, and the minimum detection limit of the banned food dye basic orange II can reach 10 -6 M, in addition, it has excellent repeatability and signal uniformity, avoiding the problem of poor signal uniformity caused by uneven distribution of "hot spots" due to agglomeration of pure noble metal nanostructure substrates.

[0009] The composite SERS substrate material prepared by the invention is used for industrial dye detection and is used as an inorganic nano material. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The powders A and Ti3C2T obtained in the examples are x Mxene powder, multilayer Ti3C2T x XRD pattern of Mxene;

[0011] Figure 2 The accordion-shaped Ti3C2T x XRD pattern of Mxene powder;

[0012] Figure 3 The accordion-shaped Ti3C2T x SEM image of Mxene powder;

[0013] Figure 4 The accordion-shaped Ti3C2T x SEM image of Mxene powder;

[0014] Figure 5The accordion-shaped Ti3C2T x SERS LOD image of Mxene powder to basic orange Ⅱ;

[0015] Figure 6 The accordion-shaped Ti3C2T x Raman spectra of Mxene powder at 10 different points on the same sample;

[0016] Figure 7 The accordion-shaped Ti3C2T x Mxene powder at 1594cm -1 Raman peak intensity spectrum at ;

[0017] Figure 8 The accordion-shaped Ti3C2T x Mxene powder at 1594cm -1 Variation of the Raman peak intensity at with concentration. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0019] Specific implementation method 1: This implementation method is a green preparation method of a composite SERS substrate for industrial dye detection, which is implemented by the following steps:

[0020] 1. Preparation of Ti3C2T x The Mxene powder is then mixed with the ferric chloride solution by magnetic stirring, and after washing and drying, a multilayer Ti3C2T x Mxene;

[0021] 2. The above multilayer Ti3C2T x Mxene was mixed with chloroauric acid solution by magnetic stirring, and after washing and drying, accordion-shaped Ti3C2T x Mxene, then placed in deionized water for ultrasonic dispersion, and then dropped onto a silicon wafer for natural drying to obtain a composite SERS substrate for industrial dye detection, thereby completing the green preparation method.

[0022] The composite SERS substrate for industrial dye detection prepared in this embodiment is used to perform laser Raman spectroscopy testing, and the process is as follows:

[0023] 2 μL to 20 μL of alkaline orange II aqueous solution was added to the composite SERS substrate for industrial dye detection, and dried naturally. Then, laser Raman spectroscopy was performed under the conditions of laser wavelength of 532 nm, exposure time of 10 s to 30 s, and laser power of 1% to 10%.

[0024] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the preparation of Ti3C2T x The process of Mxene powder is as follows:

[0025] a. Mix titanium carbide, titanium powder, aluminum powder, sodium chloride and potassium chloride and grind them, calcine them in a tube furnace under argon atmosphere, wash and dry the product to obtain powder A;

[0026] b. The powder A, nickel chloride hexahydrate, potassium chloride and sodium chloride are mixed and ground, and calcined in a tube furnace under argon atmosphere. The product is washed and dried to obtain Ti3C2T x Mxene powder;

[0027] The molar ratio of titanium carbide, titanium powder, aluminum powder, sodium chloride and potassium chloride in step a is (1.5-2):(1-1.5):(1-1.5):(1-6):(1-6);

[0028] The calcination temperature in step a is 1000° C. to 1500° C., and the calcination time is 3 to 5 hours;

[0029] The molar ratio of powder A, nickel chloride hexahydrate, potassium chloride and sodium chloride in step b is (1-1.2):(3-6):(1-5):(1-5);

[0030] The calcination temperature in step b is 700° C. to 800° C., and the calcination time is 12 to 24 hours;

[0031] The washing in steps a and b is: washing with deionized water by suction filtration for 3 to 5 times; the drying is: drying in an oven at 45° C. to 70° C. for 6 to 12 hours. The other steps and parameters are the same as those in the first embodiment.

[0032] Specific implementation method 3: This implementation method is different from specific implementation method 1 or 2 in that the concentration of the ferric chloride solution in step 1 is 0.1-0.5 mol / L. Other steps and parameters are the same as those in specific implementation method 1 or 2.

[0033] Specific embodiment 4: This embodiment is different from one of the specific embodiments 1 to 3 in that the Ti3C2T xThe mass volume ratio of Mxene powder to ferric chloride solution is (0.3-0.5) g: (10-60) mL. Other steps and parameters are the same as those in the first to third embodiments.

[0034] Specific implementation mode 5: This implementation mode is different from specific implementation modes 1 to 4 in that the magnetic stirring time in step 1 is 2 to 4 hours and the rotation speed is 500 to 1000 rpm. The other steps and parameters are the same as those in specific implementation modes 1 to 4.

[0035] Specific embodiment 6: This embodiment is different from the specific embodiments 1 to 5 in that the multilayer Ti3C2T x After Mxene and chloroauric acid solution are mixed, the concentration ratio of the two in the mixed solution is (0.001-0.005) g / mL: (0.0005-0.001) g / mL. Other steps and parameters are the same as those in the first to fifth embodiments.

[0036] Specific embodiment 7: This embodiment is different from specific embodiments 1 to 6 in that the magnetic stirring time in step 2 is 0.5h to 16h and the rotation speed is 800 to 1200rpm. Other steps and parameters are the same as those of specific embodiments 1 to 6.

[0037] Specific embodiment eight: This embodiment is different from any one of the specific embodiments one to seven in that the accordion-shaped Ti3C2T x Mxene is a powder modified by gold nanoparticles of different diameters, wherein the diameter of the gold nanoparticles is 100nm to 600nm. Other steps and parameters are the same as those of the first to seventh embodiments.

[0038] Specific embodiment 9: This embodiment is different from specific embodiments 1 to 8 in that the concentration of the solution dispersed by ultrasonic in step 2 is 0.001 g / mL to 0.01 g / mL, and the ultrasonic dispersion time is 5 to 30 min. The other steps and parameters are the same as those of specific embodiments 1 to 8.

[0039] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the volume of the droplet in step 2 is 20 μL to 100 μL, and the area of ​​the silicon wafer is (0.5 cm to 1 cm)×(0.5 cm to 1 cm). Other steps and parameters are the same as those of specific embodiments 1 to 9.

[0040] Specific embodiment 11: This embodiment differs from specific embodiments 1 to 10 in that the washing in steps 1 and 2 is performed by filtering and washing with deionized water for 3 to 5 times; the drying is performed by drying in an oven at 45°C to 70°C for 6 to 12 hours. The other steps and parameters are the same as those in specific embodiments 1 to 10.

[0041] The beneficial effects of the present invention are verified by the following examples:

[0042] Example:

[0043] A green preparation method of a composite SERS substrate for industrial dye detection is achieved by the following steps:

[0044] 1. Preparation of Ti3C2T x The Mxene powder is then mixed with the ferric chloride solution by magnetic stirring, and after washing and drying, a multilayer Ti3C2T x Mxene;

[0045] 2. The above multilayer Ti3C2T x Mxene was mixed with chloroauric acid solution by magnetic stirring, and after washing and drying, accordion-shaped Ti3C2T x Mxene, then placed in deionized water for ultrasonic dispersion, and then dropped onto a silicon wafer for natural drying to obtain a composite SERS substrate for industrial dye detection, thereby completing the green preparation method.

[0046] In step 1 of this embodiment, Ti3C2T x The process of Mxene powder is as follows:

[0047] a. Mix titanium carbide, titanium powder, aluminum powder, sodium chloride and potassium chloride and grind them, calcine them in a tube furnace under argon atmosphere, wash and dry the product to obtain powder A;

[0048] b. The powder A, nickel chloride hexahydrate, potassium chloride and sodium chloride are mixed and ground, and calcined in a tube furnace under argon atmosphere. The product is washed and dried to obtain Ti3C2T x Mxene powder;

[0049] The molar ratio of titanium carbide, titanium powder, aluminum powder, sodium chloride and potassium chloride in step a is 2:1:1.1:4:4;

[0050] The calcination temperature in step a is 1100° C. and the calcination time is 3 h;

[0051] The molar ratio of powder A, nickel chloride hexahydrate, potassium chloride and sodium chloride in step b is 1:3:2:2;

[0052] The calcination temperature in step b is 750° C. and the calcination time is 12 h;

[0053] The washing in step a is: filtering and washing with deionized water for 5 times; the drying is: drying in an oven at 65° C. for 12 hours.

[0054] The washing in step b is: filtering and washing with deionized water for 3 times; the drying is: drying in an oven at 65° C. for 8 hours.

[0055] The concentration of the ferric chloride solution in step 1 of this embodiment is 0.2 mol / L.

[0056] In step 1 of this embodiment, the Ti3C2T x The mass volume ratio of Mxene powder to ferric chloride solution is 0.45g:30mL.

[0057] The magnetic stirring time in step 1 of this embodiment is 4 hours and the rotation speed is 720 rpm.

[0058] In step 2 of this embodiment, the multilayer Ti3C2T x After Mxene and chloroauric acid solution were mixed, the concentration ratio of the two in the mixed solution was 0.0017 g / mL:0.0005 g / mL.

[0059] The magnetic stirring time in step 2 of this embodiment is 16 hours and the rotation speed is 870 rpm.

[0060] The accordion-shaped Ti3C2T x Mxene is a powder modified by gold nanoparticles of different diameters, where the diameter of the gold nanoparticles is 120nm.

[0061] The concentration of the solution dispersed by ultrasonic in step 2 of this embodiment is 0.0025 g / mL, and the ultrasonic dispersion time is 10 min.

[0062] The volume of the dropwise addition in step 2 of this embodiment is 100 μL, and the area of ​​the silicon wafer is 0.75 cm×0.75 cm.

[0063] The washing in steps 1 and 2 of this embodiment is: using deionized water for filtration and washing for 5 times; the drying is: drying in an oven at 65° C. for 6 hours.

[0064] The composite SERS substrate for industrial dye detection prepared in this embodiment is used to perform laser Raman spectroscopy testing, and the process is as follows:

[0065] 20 μL of alkaline orange II aqueous solution was added to the composite SERS substrate for industrial dye detection, and dried naturally. Then, laser Raman spectroscopy was performed under the conditions of laser wavelength of 532 nm, exposure time of 10 s, and laser power of 1%.

[0066] The powders A and Ti3C2T prepared in this example x Mxene powder, multilayer Ti3C2T x The XRD pattern of Mxene is as follows: Figure 1 As shown (wherein powder A is Figure 1 Ti3AlC2, Ti3C2T x Mxene powder Figure 1 MS-Ti3C2T x , multilayer Ti3C2T x Mxene Figure 1 It can be seen that the raw material was sintered to prepare a high-purity Ti3AlC2MAX precursor phase (powder A, containing a small amount of TiC and Al2O3 impurities). After a long period of high-temperature etching with nickel chloride, the characteristic peaks of the original Ti3AlC2 disappeared, and the (002) and (004) peaks shifted significantly to small angles, proving that the original MAX phase has been successfully etched into Ti3C2T x Mxene powder, at the same time, a large amount of metal Ni is formed. After FeCl3 treatment, Ti3C2T x The Ni element in the Mxene powder was completely removed, and high-purity multilayer Ti3C2T x Mxene powder.

[0067] The accordion-shaped Ti3C2T prepared in this example x XRD diagram of Mxene powder, such as Figure 2 As shown in Figure 2, it can be seen that the accordion-shaped Ti3C2T x Mxene powder contains a large amount of Au element.

[0068] The accordion-shaped Ti3C2T prepared in this example x SEM picture of Mxene powder, such as Figure 3 and Figure 4 As shown in the figure, it can be seen that Au nanoparticles with a diameter of about 120 nm are evenly covered on the accordion-shaped Ti3C2T x Mxene surface and gaps.

[0069] The accordion-shaped Ti3C2T prepared in this example xThe SERS LOD diagram of Mxene powder to basic orange II is as follows: Figure 5 As shown, it can be seen that the accordion-shaped Ti3C2T x The minimum detection limit (LOD) of Mxene powder material for industrial dye basic orange Ⅱ can reach 10 -6 M.

[0070] The accordion-shaped Ti3C2T prepared in this example x Raman spectra of Mxene powder at 10 different points on the same sample ( Figure 6 ) and at 1594cm -1 The Raman peak intensity at Figure 7 ) and its variation with concentration ( Figure 8 ), it can be seen that the accordion-shaped Ti3C2T x Mxene powder as SERS substrate for detecting basic orange II dye has good signal uniformity and repeatability. -1 The relative standard deviation (RSD) value of repeated tests of the Raman peak intensity at the position does not exceed 20%, and its signal intensity shows a linear function downward trend as the negative logarithm of the concentration increases.

[0071] In this paper, a composite SERS substrate material for industrial dye detection was successfully prepared by a green and simple method, using Ti3C2T3 with a large specific surface area and adjustable surface. x Mxene material, as a substrate for loading traditional SERS substrate material gold nanoparticles, solves the problems of existing precious metal SERS substrates such as strong fluorescence, poor biocompatibility, high price and easy oxidation, and achieves good SERS detection effect for industrial dye basic orange II.

Claims

1. A green preparation method of a composite SERS substrate for industrial dye detection, characterized in that It is implemented as follows:

1. Preparation of Ti3C2T x The Mxene powder is then mixed with the ferric chloride solution by magnetic stirring, and after washing and drying, a multilayer Ti3C2T x Mxene; 2. The above multilayer Ti3C2T x Mxene was mixed with chloroauric acid solution by magnetic stirring, and after washing and drying, accordion-shaped Ti3C2T x Mxene, then ultrasonically dispersed in deionized water, and then dropped onto a silicon wafer and naturally dried to obtain a composite SERS substrate for industrial dye detection, thus completing the green preparation method; The concentration of the ferric chloride solution in step 1 is 0.1-0.5 mol / L; Ti3C2T x The mass volume ratio of Mxene powder to ferric chloride solution is (0.3-0.5) g: (10-60) mL; The magnetic stirring time in step 1 is 2 to 4 hours, and the rotation speed is 500 to 1000 rpm; The multilayer Ti3C2T x After Mxene and chloroauric acid solution are mixed, the concentration ratio of the two in the mixed solution is (0.001~0.005) g / mL:(0.0005~0.001) g / mL; The magnetic stirring time in step 2 is 0.5h to 16h, and the speed is 800 to 1200rpm; The concentration of the ultrasonically dispersed solution in step 2 is 0.001 g / mL to 0.01 g / mL, and the ultrasonic dispersion time is 5 to 30 min; The volume of the dropwise addition in step 2 is 20 μL to 100 μL, and the area of ​​the silicon wafer is (0.5 cm to 1 cm)×(0.5 cm to 1 cm).

2. The green preparation method of a composite SERS substrate for industrial dye detection according to claim 1, characterized in that The accordion-shaped Ti3C2T x Mxene is a powder modified by gold nanoparticles of different diameters, wherein the diameter of the gold nanoparticles is 100nm to 600nm.

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