A fluorescent composite nanomaterial for detecting triclosan, and its preparation method and application

Abstract

The present invention discloses a fluorescent composite nanomaterial for detecting triclosan and its preparation method and application, which belongs to the technical field of triclosan detection. The preparation method provided by the present invention is as follows: 2+ Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine, and yttrium chloride are mixed in a solvent, stirred for reaction, and the resulting solution is centrifuged. The precipitate is added to a mixed solution of methanol and acetic acid, stirred for a set time, and then centrifuged and washed to obtain the fluorescent composite luminescent nanomaterial prepared by the present invention. The fluorescent composite luminescent nanomaterial can achieve specific detection of triclosan, has high measurement stability, a wide measurement range, a short response time, and can be detected on-site, which is convenient, fast, and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of triclosan detection, and in particular to a fluorescent composite nanomaterial for detecting triclosan, a preparation method thereof, and an application thereof. Background Art

[0002] The information disclosed in the background of the invention is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Triclosan is a slightly aromatic, high-purity, white crystalline powder with very low volatility. It is slightly soluble in water, moderately soluble in dilute alkali, and highly soluble in many organic solvents. Dissolving it in a water-soluble solvent or surfactant can produce a transparent, concentrated liquid product. Triclosan is a broad-spectrum antimicrobial agent widely used in cosmetics, detergents, medical disinfectants, and health care products. Triclosan can accumulate in food through contaminated water, soil, food packaging, and cleaning steps during food processing, leading to ingestion and health hazards. Therefore, the development of simple, rapid, and sensitive detection methods to strengthen triclosan monitoring is crucial.

[0004] Current methods for detecting triclosan primarily include high-performance liquid chromatography, liquid chromatography-tandem mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry. These methods require expensive instrumentation, complex operation, and long analysis times. They also require specialized pretreatment prior to analysis, making them unsuitable for on-site detection. Electrochemical detection has also been reported. This involves modifying an electrode surface with a specific detection substance and establishing a standard curve based on the redox current at varying concentrations, thereby enabling the detection of triclosan concentrations. However, electrochemical detection methods suffer from relatively long response times, poor stability, and complex maintenance. Fluorescence detection offers a short response time, good stability, and relatively simple maintenance. It also allows for on-site detection and has high sensitivity. However, reports on fluorescence detection methods for triclosan are limited. Summary of the Invention

[0005] In view of this, the present invention provides a fluorescent composite nanomaterial for detecting triclosan, a preparation method thereof, and an application thereof. The fluorescent composite nanomaterial for detecting triclosan provided by the present invention has the advantage of strong fluorescence emission, and can achieve accurate measurement of triclosan in the range of 1 to 950 mg / L, with high measurement accuracy and strong specificity.

[0006] In a first aspect, the present invention provides a method for preparing a fluorescent composite nanomaterial for detecting triclosan, comprising the following steps:

[0007] Preparation of amino-modified and Mn-doped2+ Zn2GeO4 nanoparticles and CuInSe2 quantum dots modified with carboxyl groups and doped with Zn;

[0008] The amino group-modified and Mn-doped 2+ Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride are mixed in a solvent, stirred to react, and then the reaction solution is centrifuged, and the precipitate is added to a mixed solution of methanol and acetic acid, stirred for a set time, and then centrifuged and washed to obtain the product.

[0009] In a second aspect, the present invention provides a fluorescent composite nanomaterial for detecting triclosan prepared by the above preparation method.

[0010] In a third aspect, the present invention provides an application of the fluorescent composite nanomaterial for detecting triclosan in the detection of triclosan, and the application method is as follows:

[0011] The fluorescent composite nanomaterial for detecting triclosan is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and a standard curve is established based on the relationship between the fluorescence intensity at 525 to 540 nm of the emission spectrum and the concentration;

[0012] Then the triclosan solution to be tested is mixed with the fluorescent composite nanomaterial for detecting triclosan, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and the concentration of the triclosan solution to be tested is determined according to the standard curve.

[0013] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0014] The present invention utilizes the amide bond formed by dehydration condensation of amino and carboxyl groups to connect Zn2GeO4 with amino groups on the surface and Zn-CuInSe2 quantum dots with carboxyl groups on the surface, and then wraps Y(OH) x The fluorescent composite nanomaterial prepared by this method is mixed with triclosan at a certain concentration gradient. Upon excitation, the peak value of the emission spectrum produced by the fluorescent composite luminescent nanomaterial exhibits a linear change with increasing triclosan concentration. The method has high measurement accuracy and a wide measurement range, enabling accurate measurement within a range of 1 to 950 mg / L. Furthermore, the method has good selectivity and is capable of specific detection of triclosan. The method utilizes a fluorescence method for measurement, which has high measurement stability, a short response time, and allows for on-site detection, making it convenient, quick, and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute undue limitations thereon. It is obvious that one of ordinary skill in the art could derive other drawings based on these drawings without inventive effort.

[0016] Figure 1 is Zn2GeO4:Mn in step (4) of Example 1 of the present invention 2+ Scanning electron microscope images of nanoparticles;

[0017] Figure 2 is the Zn2GeO4:Mn in step (4) of Example 1 of the present invention 2+ Emission spectra of nanoparticles;

[0018] Figure 3 is the Zn2GeO4:Mn in step (4) of Example 1 of the present invention 2+ Nanoparticles and amino-modified Zn2GeO4:Mn in step (7) 2+ Fourier transform infrared spectrum of nanoparticles;

[0019] Figure 4 This is an emission spectrum of Zn-CuInSe2 quantum dots prepared in Example 2 of the present invention under an excitation light source of 365nm and 8W;

[0020] Figure 5 This is a transmission electron microscope image of Zn-CuInSe2 quantum dots prepared in Example 2 of the present invention;

[0021] Figure 6 This is a Fourier infrared spectrum of Zn-CuInSe2 quantum dots and Zn-CuInSe2-COOH quantum dots prepared in Example 2 of the present invention;

[0022] Figure 7 is a scanning electron microscope image of the fluorescent composite nanomaterial prepared in Example 3 of the present invention;

[0023] Figure 8 is a Fourier infrared spectrum of the fluorescent composite nanomaterial prepared in Example 3 of the present invention;

[0024] Figure 9 This is an emission spectrum of the fluorescent composite nanomaterial prepared in Example 3 of the present invention;

[0025] Figure 10 This is a graph showing the relationship between the emission intensity of the fluorescent composite nanomaterial prepared in Example 3 of the present invention at 532 nm and the concentration of triclosan, with an excitation light source of 254 nm and a power of 8 W;

[0026] Figure 11 This is a graph showing the specificity test results of the fluorescent composite nanomaterial prepared in Example 3 of the present invention for triclosan. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0028] The present invention provides a method for preparing a fluorescent composite nanomaterial for detecting triclosan, comprising the following steps:

[0029] Preparation of amino-modified and Mn-doped 2+ Zn2GeO4 nanoparticles and CuInSe2 quantum dots modified with carboxyl groups and doped with Zn;

[0030] The amino group-modified and Mn-doped 2+ Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride are mixed in a solvent, stirred to react, and then the reaction solution is centrifuged, and the precipitate is added to a mixed solution of methanol and acetic acid, stirred for a set time, and then centrifuged and washed to obtain the product.

[0031] In the above method of the present invention, the modified amino group and doped with Mn 2+ The Zn2GeO4 nanoparticles and the CuInSe2 quantum dots modified with carboxyl groups and doped with Zn were coupled by dehydration condensation under the action of the condensation agent to form Zn2GeO4:Mn 2+ -Zn-CuInSe2 nanoparticles. Yttrium chloride generates Y(OH) in the alkaline environment generated by the hydrolysis of hexamethylenetetramine and the hydroxide ions provided by the water in the system. x , Y(OH) x During the formation process, it will react with Zn2GeO4:Mn 2+ -Zn-CuInSe2 nanoparticles interact with each other on the surface (such as electrostatic attraction, chemical bonding or physical adsorption), gradually aggregate and grow on the surface, and finally form a Zn2GeO4:Mn 2+ -Y(OH) on Zn-CuInSe2 nanoparticles x layer, and obtain Zn2GeO4:Mn 2+ -Zn-CuInSe2@Y(OH) x Fluorescent composite nanomaterials. After Zn2GeO4 forms nanoparticles, it provides a stable structural framework for the entire system, making the doped Mn 2+It can maintain a relatively stable state in its lattice, which is conducive to the stability and reproducibility of fluorescence performance. 2+ , Zn-CuInSe2 and Y(OH) x After the three are combined, through their respective fluorescence characteristics and the energy transfer and synergistic effect between each other, they can produce stronger, more stable and more characteristic fluorescence signals, greatly improving the sensitivity and accuracy of fluorescence detection, and helping to detect target substances at lower concentrations. The rich fluorescence emission characteristics and various physical and chemical properties after their combination make this fluorescent composite nanomaterial applicable to a wider range of detection objects and detection environments. By rationally designing and regulating the Zn2GeO4:Mn 2+ , Zn-CuInSe2 and Y(OH) x The composition, structure, and surface properties of the molecule enable it to have higher selectivity and affinity for specific target substances. The synergistic effect of the three enables highly specific detection of specific biomarkers, reduces interference from other substances, and improves the reliability and accuracy of detection.

[0032] During the preparation process of the fluorescent composite nanomaterial of the present invention, the addition of triclosan enables the fluorescent composite nanomaterial to generate coordination corresponding to triclosan (equivalent to "holes"), and the triclosan is subsequently removed by washing with methanol and acetic acid, thereby forming a pore structure with a specific shape and size on the surface of the fluorescent composite nanomaterial, so as to facilitate subsequent applications such as adsorption, separation or detection of specific substances (triclosan).

[0033] In the present invention, the modified with amino group and doped with Mn 2+ The ratio of Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine, and yttrium chloride is (180-220) mg: (40-60) mg: (8-12) mg: (0.8-1.2) mg: (10-15) mg: (2-4) mg: (4-6) mg; the solvent is selected from cyclohexane and water. Cyclohexane can serve as a good solvent to fully dissolve and uniformly mix the reactants, thereby promoting the reaction. Zn-doped CuInSe2 dissolves in cyclohexane, and triclosan is an organic substance that is not easily soluble in water. Cyclohexane can serve as a good organic solvent to evenly disperse triclosan, allowing it to better contact and interact with other substances.

[0034] In the present invention, the stirring reaction time is 5 to 10 hours, and the stirring reaction temperature is 60 to 75° C.; in the step of taking the precipitate, adding a mixed solution of methanol and acetic acid, and stirring for a set time, the stirring time is 12 to 30 hours.

[0035] In the present invention, the modified with amino group and doped with Mn 2+ The preparation method of Zn2GeO4 nanoparticles is as follows:

[0036] Mix zinc salt, manganese salt and dilute nitric acid, then add Na2GeO3, adjust the pH to 7.2-7.9 by adding alkali solution, carry out hydrothermal synthesis reaction, and purify to obtain doped Mn 2+ Zn2GeO4 nanoparticles; then doped with Mn 2+ Zn2GeO4 nanoparticles reacted with dopamine under alkaline conditions to obtain Zn2GeO4 nanoparticles modified with amino groups and doped with Mn 2+ The present invention does not impose any special restrictions on the selection of zinc salt and manganese salt, and zinc salts and manganese salts commonly used in the art can be used. The present invention preferably uses zinc nitrate and manganese chloride. The present invention does not impose any special restrictions on the purification process, and purification methods commonly used in the art can be used. The doped Mn 2+ The dosage ratio of Zn2GeO4 nanoparticles to dopamine is 400:(1-2), and the pH of the alkaline condition is 8.0-9.0. Under alkaline conditions, dopamine can undergo self-polymerization to generate polydopamine, which has very good adhesion properties and contains a large number of amino groups. Triethylamine is preferably added to the reaction system during the dopamine polymerization process, which can not only adjust the pH but also further introduce amino groups. The present invention uses dopamine reaction to modify the amino group to give the doped Mn 2+ The surface of Zn2GeO4 nanoparticles brings unique properties and activity. It not only introduces amino groups, but also forms a special organic layer on the surface of the nanoparticles without destroying the internal structure of the nanoparticles, thereby maintaining the original optical, electrical and other properties of the nanoparticles.

[0037] In the present invention, the preparation method of the CuInSe2 quantum dots modified with carboxyl groups and doped with Zn is as follows:

[0038] Under the protection of inert gas, zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene and n-dodecyl mercaptan are mixed and heated to react, and then a mixture of Se powder, oleylamine and n-dodecyl mercaptan is added, and the heating reaction is continued. After cooling, purification is performed to obtain Zn-doped CuInSe2 quantum dots; the Zn-doped CuInSe2 quantum dots are then mixed and reacted with nitrosotetrafluoroborate, and then mixed and reacted with polyacrylic acid to obtain CuInSe2 quantum dots modified with carboxyl groups and doped with Zn.

[0039] Nitrogen is preferably used as the inert gas in the present invention to prevent the presence of oxygen from adversely affecting material synthesis. The ratio of zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene, Se powder, oleylamine, and n-dodecanethiol is (0.08-0.12) mmol: (0.02-0.04) mmol: (0.08-0.12) mmol: (0.8-1.2) mL: (6-10) mL: (0.17-0.21) mmol: (0.4-0.6) mL: (1-2) mL. The ratio of Zn-doped CuInSe2 quantum dots, nitrosotetrafluoroborate, and polyacrylic acid is (4-8) mg: (180-220) mg: (180-220) mg. Nitrosotetrafluoroborate can remove surface organic ligands and activate the quantum dot surface. Polyacrylic acid is connected to the Zn-doped CuInSe2 quantum dots through coordination. It has abundant carboxyl groups for reacting with amino groups. The polyacrylic acid molecular chain contains a large number of carboxyl groups (-COOH), and the oxygen atoms in the carboxyl groups have lone pairs of electrons. Under appropriate conditions, the oxygen atoms on the carboxyl groups can donate lone pairs of electrons to the empty orbitals of the metal ions on the surface of the quantum dots to form coordination bonds. This coordination effect enables polyacrylic acid to be tightly connected to the surface of the Zn-doped CuInSe2 quantum dots to form a stable complex. When polyacrylic acid is connected to the surface of the quantum dots, its abundant carboxyl groups can react with substances containing amino groups (-NH2) (modified with amino-doped Mn 2+ Zn2GeO4 nanoparticles) undergo dehydration condensation reaction.

[0040] In the preparation process of Zn-doped CuInSe2 quantum dots of the present invention, the post-mixing heating reaction is performed at a temperature of 150-170°C for 20-60 minutes, and the continued heating reaction is performed at a temperature of 150-170°C for 10-30 minutes. Zn-doped CuInSe2 quantum dots are prepared through a solvothermal reaction.

[0041] The present invention also provides a fluorescent composite nanomaterial for detecting triclosan prepared by the above preparation method. The fluorescent composite nanomaterial (Zn2GeO4: Mn 2+ -Zn-CuInSe2@Y(OH) x ) has the advantage of strong fluorescence emission. Under the excitation of 254nm laser, it has a green light emission peak at 525-540nm, and the fluorescence intensity at the peak shows a good linear relationship with the concentration of triclosan, so it can be used for the detection of triclosan concentration.

[0042] The present invention also provides the use of the fluorescent composite nanomaterial for detecting triclosan in the detection of triclosan, and the application method is as follows:

[0043] The fluorescent composite nanomaterial for detecting triclosan is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and a standard curve is established based on the relationship between the fluorescence intensity at 525 to 540 nm of the emission spectrum and the concentration;

[0044] Then the triclosan solution to be tested is mixed with the fluorescent composite nanomaterial for detecting triclosan, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and the concentration of the triclosan solution to be tested is determined according to the standard curve.

[0045] The technical solution of the present invention is further described below with reference to specific examples. The present invention has no particular limitation on the sources of the reagents used in the following examples, and commercially available products known to those skilled in the art can be used. The room temperature in the following examples refers to 25±3°C.

[0046] Example 1

[0047] This embodiment provides a Zn2GeO4:Mn modified with amino groups. 2+ (Zn2GeO4:Mn 2+ -NH2) nanoparticles.

[0048] (1) Add Zn(NO3)2 (1.98 mmol) and MnCl2 (0.02 mmol) to a beaker, then add 300 μL of 1% (mass percentage) dilute nitric acid and 20 mL of water and stir.

[0049] (2) Dissolve 10 mmol of NaOH in 10 mL of aqueous solution until the NaOH is completely dissolved. Add 2 mmol of GeO2 and stir to obtain a Na2GeO3 solution. Add 5.5 mL of the above solution to the solution in step (1) using a syringe and stir the mixed solution for 30 minutes.

[0050] (3) Adjust the pH of the solution to 7.58 with 1 wt% sodium hydroxide, stir for 30 minutes, and transfer to a hydrothermal reactor at 220°C for 16 hours.

[0051] (4) The solution after the reaction was centrifuged at 10000 r / min × 10 min, washed with water and dried to obtain Zn2GeO4:Mn 2+ Nanoparticles.

[0052] (5) 400 mg Zn2GeO4:Mn 2+After the nanoparticles were wet-ground, 10 mL of NaOH solution was added, ultrasonicated for 30 min, stirred for 24 h, and then centrifuged at a low speed of 3000 r / min for 10 min to remove large particles and impurities (nanoparticles were in the suspension). The suspension was then centrifuged at a high speed of 12000 r / min for 15 min, the precipitate was collected, washed once, and then ultrasonically dispersed in 20 mL of water to obtain Zn2GeO4:Mn 2+ Aqueous dispersion.

[0053] (6) Adjust the pH of Tris-HCl (tris(hydroxymethyl)aminomethane hydrochloride) buffer to 8.5, take 20mL Zn2GeO4:Mn 2+ To the aqueous dispersion, 1.4 mL of a 1 mg / mL dopamine aqueous solution was added, and the mixture was stirred at room temperature for 2 h.

[0054] (7) After the reaction, the reaction solution was centrifuged at a low speed of 3000 r / min for 5 minutes to remove large particles and impurity precipitation. The supernatant was dispersed in 350 mL of tris(hydroxymethyl)aminomethane hydrochloride) with a pH of 8.5, and 1.5 mL of ethylenediamine was added. After mixing, the mixture was stirred in the dark for 24 hours. The mixture was centrifuged at a high speed of 12000 r / min for 15 minutes, washed twice with water, and dried to obtain Zn2GeO4:Mn modified with amino groups. 2+ Nanoparticles.

[0055] Figure 1 The Zn2GeO4:Mn 2+ Scanning electron microscope image of nanoparticles. It can be seen from the image that the nanoparticles are rod-shaped, with a particle length of 50 to 100 nm and a diameter of 20 to 40 nm.

[0056] Figure 2 The Zn2GeO4:Mn 2+ The emission spectrum of nanoparticles, the excitation light source used is 254nm, the power is 8W, it can be seen from the figure that Zn2GeO4:Mn 2+ The emission peak of the nanoparticles is 532 nm.

[0057] Figure 3 The Zn2GeO4:Mn 2+ Nanoparticles and amino-modified Zn2GeO4:Mn in step (7) 2+ The Fourier transform infrared spectrum (FTIR) of the nanoparticles shows that Zn2GeO4:Mn 2+ The absorption peak of the surface functional group (-OH) is 3296 cm -1 , Zn2GeO4:Mn 2+The absorption peak of -NH2 surface functional group (-OH) is 3310 cm -1 , 1407cm -1 The absorption peak of -NH2 is the absorption peak of -OH functional group. The change of the position of -OH functional group and the appearance of -NH2 absorption peak indicate that the Zn2GeO4:Mn 2+ The amino treatment was successful.

[0058] Example 2

[0059] This embodiment provides a method for preparing CuInSe2 (Zn-CuInSe2-COOH) quantum dots modified with carboxyl groups and doped with Zn.

[0060] (1) Add 0.1 mmol of anhydrous zinc acetate, 0.03 mmol of cuprous iodide, 0.1 mmol of indium acetate, 1 mL of oleic acid, 8 mL of octadecene, and 1 mL of n-dodecanethiol to a four-necked flask. Evacuate the flask for 10 minutes, stir with a high-temperature magnetic stirrer, and heat to 160°C under nitrogen for 30 minutes.

[0061] (2) 0.19 mmol Se powder was dissolved in 0.5 mL oleylamine and 0.5 mL n-dodecyl mercaptan. The mixture was injected into the four-necked flask in step (1) using a syringe. The mixture was stirred at 160° C. for 20 minutes and then cooled to room temperature.

[0062] (3) Add 10 mL of ethanol to a four-necked flask cooled to room temperature, then centrifuge at 12,000 rpm for 10 minutes. Remove the precipitate, add 15 mL of cyclohexane, and sonicate. Centrifuge at 4,500 rpm for 5 minutes. Collect the supernatant to obtain 15 mL of a cyclohexane dispersion of Zn-CuInSe2 (containing approximately 20.5 mg of Zn-CuInSe2).

[0063] (4) Take a 50mL centrifuge tube, add 6mL cyclohexane and 10mL N,N-dimethylformamide, and stir for 2 minutes; then add 200mg of tetrafluoroborate nitrosamine and stir for 10 minutes; then add 5mL of Zn-CuInSe2 cyclohexane dispersion and stir for about 30 minutes. After stirring, irradiate with a laser. If the lower half glows, stirring is complete (dispersed in DMF after tetrafluoroborate nitrosamine treatment). If the upper half glows, stirring needs to be continued. After stirring, centrifuge at 12000r / min for 10 minutes, take the precipitate, add 5mL N,N-dimethylformamide, and ultrasonicate to make it uniformly dispersed to obtain Zn-CuInSe2 N,N-dimethylformamide dispersion.

[0064] (5) Weigh 200 mg of polyacrylic acid in a beaker, add 10 mL of N,N-dimethylformamide, sonicate, and add 5 mL of the N,N-dimethylformamide dispersion of Zn-CuInSe2 from step (4). Stir overnight and centrifuge at 12,000 rpm for 10 minutes. Wash the precipitate once and then disperse it in 20 mL of water to obtain an aqueous Zn-CuInSe2-COOH dispersion.

[0065] Figure 4 This is the emission spectrum of the Zn-CuInSe2 quantum dots prepared in this example under an excitation light source of 365nm and 8W. It can be seen that the emission peak of the Zn-CuInSe2 quantum dots is 452nm.

[0066] Figure 5 This is a transmission electron microscope (TEM) image of the Zn-CuInSe2 quantum dots prepared in this example, which have a size of about 3 to 5 nm.

[0067] Figure 6 The Fourier transform infrared spectra of Zn-CuInSe2 quantum dots and Zn-CuInSe2-COOH quantum dots prepared in this example show that the Zn-CuInSe2-COOH quantum dots after reacting with polyacrylic acid have a 1661.01 cm -1 The absorption peak belongs to the carbonyl absorption peak, indicating that the modification is successful.

[0068] Example 3

[0069] This embodiment provides a fluorescent composite nanomaterial Zn2GeO4-Zn-CuInSe2@Y(OH)2 for detecting triclosan. x Preparation method.

[0070] (1) Take the amino-modified Zn2GeO4:Mn 2+ 200 mg of nanoparticles were dispersed in 10 mL of deionized water to obtain Zn2GeO4:Mn 2+ -NH2 aqueous dispersion.

[0071] (2) Add 10 mL of Zn2GeO4:Mn 2+ A mixture of an aqueous dispersion of NH2-HCl, 10 mg of triclosan, 1 mg of citric acid, 12 mg of sodium salicylate, 3 mg of hexamethylenetetramine, 5 mg of yttrium chloride hexahydrate, 5 mL of cyclohexane, and 5 mL of the aqueous dispersion of Zn-CuInSe2-COOH from Example 2 was stirred at room temperature for 1 hour, then heated to 70°C and stirred for 7 hours. Then, 10 mL of ethanol was added and the lid was opened to evaporate the ethanol and cyclohexane.

[0072] (3) Centrifuge at 12000 r / min for 10 minutes to obtain the precipitate. Add 20 mL of methanol and acetic acid at a volume ratio of 9:1 and stir for 24 hours. Then centrifuge at 11000 r / min for 10 minutes, wash twice and disperse in 5 mL of water to obtain Zn2GeO4-Zn-CuInSe2@Y(OH) x Fluorescent composite nanomaterial aqueous solution.

[0073] Figure 7 The scanning electron microscope image of the fluorescent composite nanomaterial prepared in this example shows that the nanoparticles are spherical and have a size of about 30-50 nm.

[0074] Figure 8 This is the Fourier transform infrared spectrum (FTIR) of the fluorescent composite nanomaterial prepared in this example, 3351.57cm -1 1637.85cm -1 The absorption peak at is a typical stretching vibration peak of an amide bond, indicating that an amide bond is formed through dehydration condensation between the amino group and the carboxyl group.

[0075] Figure 9 This is the emission spectrum of the fluorescent composite nanomaterial prepared in this example. The excitation light source used is 254nm and the power is 8W. The results show that the emission peak of the fluorescent composite nanomaterial is 532nm.

[0076] Test example

[0077] 1. Using Zn2GeO4-Zn-CuInSe2@Y(OH) x Fluorescent composite nanomaterials to detect triclosan concentration:

[0078] (1) Prepare triclosan aqueous solutions of different concentrations from 1 to 950 mg / L, take 150 μL of each concentration and add it to a 1.5 mL centrifuge tube, and then add 150 μL of Zn2GeO4-Zn-CuInSe2@Y(OH)2O4 prepared in Example 3 to each centrifuge tube. x Fluorescent composite nanomaterial aqueous solution.

[0079] (2) Under 254 nm, 8 W laser excitation, the emission intensity (330-700 nm) of all the solutions in the centrifuge tubes was tested, and a linear relationship between the triclosan concentration and the emission intensity of the fluorescent composite nanomaterial at 532 nm was obtained, as shown in FIG. Figure 10 The fitted linear equation is y = -2.511x + 5801.564, and the goodness of fit is R 2 =0.989, indicating that the regression line fits the test value well.

[0080] 2. Zn2GeO4-Zn-CuInSe2@Y(OH) of Example 3 x Specificity test of triclosan by fluorescent composite nanomaterials:

[0081] (1) Prepare aqueous solutions of triclocarban, triclosan, 2-bromo-nitrophenol, bisphenol A, dopamine hydrochloride, and ascorbic acid serum at the same concentration (850 mg / L), take 150 μL of each and add them to a 1.5 ml centrifuge tube, and then add 150 μL of Zn2GeO4-Zn-CuInSe2@Y(OH)2O4 prepared in Example 3 to each centrifuge tube. x Fluorescent composite nanomaterial aqueous solution.

[0082] (2) Under 254 nm, 8 W laser excitation, the emission intensity of 150 μL of fluorescent composite nanomaterials at 532 nm was tested.

[0083] (3) Under 254nm, 8W laser excitation, test the emission peak intensity of all solutions in the centrifuge tubes at 532nm, and record the difference between the emission intensity of the solution and the emission intensity of the fluorescent composite nanomaterial, that is, the emission intensity of the solution minus the emission intensity of the fluorescent composite nanomaterial. The test results are as follows: Figure 11 As shown, it can be seen that the fluorescent composite nanomaterial prepared by the present invention has good detection specificity for triclosan.

[0084] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for preparing a fluorescent composite nanomaterial for detecting triclosan, characterized in that: The steps include: Preparation of amino-modified and Mn-doped 2+ Zn2GeO4 nanoparticles and CuInSe2 quantum dots modified with carboxyl groups and doped with Zn; The amino group-modified and Mn-doped 2+ Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride are mixed in a solvent and stirred for reaction. The stirring reaction time is 5 to 10 hours and the stirring reaction temperature is 60 to 75°C. The solution after the reaction is then centrifuged, and the precipitate is added to a mixed solution of methanol and acetic acid, stirred for a set time, and then centrifuged and washed to obtain the product.

2. The preparation method according to claim 1, wherein The modified with amino group and doped with Mn 2+ The dosage ratio of Zn2GeO4 nanoparticles, CuInSe2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride is (180~220) mg: (40~60) mg: (8~12) mg: (0.8~1.2) mg: (10~15) mg: (2~4) mg: (4~6) mg; the solvent is selected from cyclohexane and water.

3. The preparation method according to claim 1, wherein In the step of taking the precipitate, adding the mixed solution of methanol and acetic acid, and stirring for a set time, the stirring time is 12 to 30 hours.

4. The preparation method according to claim 1, wherein The modified with amino group and doped with Mn 2+ The preparation method of Zn2GeO4 nanoparticles is as follows: Mix zinc salt, manganese salt and dilute nitric acid, then add Na2GeO3, adjust the pH to 7.2~7.9 by adding alkali solution, carry out hydrothermal synthesis reaction, and purify to obtain doped Mn 2+ Zn2GeO4 nanoparticles; then doped with Mn 2+ Zn2GeO4 nanoparticles reacted with dopamine under alkaline conditions to obtain Zn2GeO4 nanoparticles modified with amino groups and doped with Mn 2+ Zn2GeO4 nanoparticles; wherein the molar ratio of zinc salt to manganese salt is (95~99.5): (0.5~5).

5. The preparation method according to claim 4, wherein The doped Mn 2+ The ratio of Zn2GeO4 nanoparticles to dopamine is 400: (1-2), and the pH of the alkaline condition is 8.0-9.

0.

6. The preparation method according to claim 1, wherein The preparation method of the CuInSe2 quantum dots modified with carboxyl groups and doped with Zn is as follows: Under the protection of inert gas, zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene and n-dodecyl mercaptan are mixed and heated to react, and then a mixture of Se powder, oleylamine and n-dodecyl mercaptan is added, and the heating reaction is continued. After cooling, purification is performed to obtain Zn-doped CuInSe2 quantum dots; the Zn-doped CuInSe2 quantum dots are then mixed and reacted with nitrosotetrafluoroborate, and then mixed and reacted with polyacrylic acid to obtain CuInSe2 quantum dots modified with carboxyl groups and doped with Zn.

7. The preparation method according to claim 6, wherein The dosage ratio of zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene, Se powder, oleylamine and n-dodecanethiol is (0.08~0.12) mmol: (0.02~0.04) mmol: (0.08~0.12) mmol: (0.8~1.2) mL: (6~10) mL: (0.17~0.21) mmol: (0.4~0.6) mL: (1~2) mL; the dosage ratio of Zn-doped CuInSe2 quantum dots, nitrosotetrafluoroborate and polyacrylic acid is (4~8) mg: (180~220) mg: (180~220) mg.

8. The preparation method according to claim 6, wherein The reaction temperature of the post-mixing heating reaction is 150-170° C., and the reaction time is 20-60 min; the reaction temperature of the continued heating reaction is 150-170° C., and the reaction time is 10-30 min.

9. A fluorescent composite nanomaterial for detecting triclosan prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the fluorescent composite nanomaterial for detecting triclosan according to claim 9 in the detection of triclosan, characterized in that: The application method is as follows: The fluorescent composite nanomaterial for detecting triclosan is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and a standard curve is established based on the relationship between the fluorescence intensity at 525-540 nm of the emission spectrum and the concentration; Then the triclosan solution to be tested is mixed with the fluorescent composite nanomaterial for detecting triclosan, an excitation light source with a wavelength of 254 nm is used as the excitation light, the emission spectrum is detected, and the concentration of the triclosan solution to be tested is determined according to the standard curve.

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