Fluorescent composite nano material for detecting triclosan as well as preparation method and application of fluorescent composite nano material

Abstract

The invention discloses a fluorescent composite nano material for detecting triclosan as well as a preparation method and application of the fluorescent composite nano material, and belongs to the technical field of triclosan detection. The preparation method provided by the invention comprises the following steps: uniformly mixing Zn2GeO4 nanoparticles modified with amino and doped with Mn < 2 + >, CuInSe2 quantum dots modified with carboxyl and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride in a solvent, stirring for reaction, then centrifuging the solution after reaction, taking the precipitate, adding the precipitate into a mixed solution of methanol and acetic acid, stirring for reaction, and drying to obtain the Zn2GeO4 / CuInSe2 quantum dot composite photocatalyst. Stirring for a set time, and then centrifuging and washing to obtain the product. The fluorescent composite light-emitting nano material prepared by the invention can realize specific detection of triclosan, is high in measurement stability, wide in measurement range, short in response time, capable of realizing field detection, convenient and rapid, and low in detection 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 art of the present invention is only intended to enhance the overall understanding of the present invention, and is not necessarily regarded as an admission or an indication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Triclosan is a highly pure white crystalline powder with a slight aroma, very low volatility, slightly soluble in water, moderately soluble in dilute alkali, and highly soluble in many organic solvents. It can be made into a transparent concentrated liquid product after being dissolved in a water-soluble solvent or a surfactant. Triclosan is a broad-spectrum antibacterial agent and is widely used in cosmetics, detergents, medical disinfection, and health care products. Triclosan can be residues in food through contaminated water sources, soil, food packaging, and cleaning links in food processing, and thus be ingested by the human body, endangering human health. Therefore, it is very necessary to develop simple, rapid, and sensitive detection methods to strengthen the monitoring of triclosan.

[0004] Currently, the methods for detecting triclosan mainly include high performance liquid chromatography, liquid chromatography-tandem mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry, etc. These methods all require expensive instruments, and are complex in operation, long in analysis time, and need some special pretreatment before analysis, which is not conducive to on-site detection. There are also research reports on electrochemical detection methods, that is, by modifying a specific detection substance on the electrode surface, establishing a standard curve according to the magnitude of the redox current at different concentrations, so as to achieve the detection of triclosan concentration. However, the electrochemical detection method has problems such as a slightly longer response time, poor stability, and relatively complex maintenance. The fluorescence detection method has a short response time, good stability, relatively simple maintenance, and can achieve on-site detection with high detection sensitivity. However, there are few reports on the fluorescence detection method for triclosan at present. 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 advantages of strong fluorescence emission, can accurately measure triclosan in the range of 1-950 mg / L, has high measurement accuracy and strong specificity.

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

[0007] Prepare the one modified with amino group and doped with Mn2+ Zn of 2 GeO 4 nanoparticles and carboxyl group - modified and Zn - doped CuInSe 2 quantum dots;

[0008] Mix the amino group - modified and Mn - doped Zn 2+ Zn of 2 GeO 4 nanoparticles, carboxyl group - modified and Zn - doped CuInSe 2 quantum dots, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride in a solvent, stir and react, then centrifuge the reaction solution, take the precipitate, add it to a mixed solution of methanol and acetic acid, stir for a set time, and then centrifuge and wash to obtain.

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

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

[0011] Mix the fluorescent composite nanomaterial for detecting triclosan with triclosan solutions of different concentrations, use a 254 - nm excitation light source as the excitation light, detect the emission spectrum, and establish a standard curve according to the relationship between the fluorescence intensity and the concentration at 525 - 540 nm in the emission spectrum;

[0012] Then mix the triclosan solution to be detected with the fluorescent composite nanomaterial for detecting triclosan, use a 254 - nm excitation light source as the excitation light, detect the emission spectrum, and determine the concentration of the triclosan solution to be detected according to the standard curve.

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

[0014] The present invention uses the amide bond formed by the dehydration condensation of amino groups and carboxyl groups to connect the amino - group - modified Zn 2 GeO 4 with the carboxyl - group - modified Zn - CuInSe 2 quantum dots, and then wrap Y(OH) xA fluorescent composite nanomaterial is formed; after the fluorescent composite luminescent nanomaterial prepared by this method is mixed with triclosan at a certain concentration gradient, the peak value of the emission spectrum generated after excitation shows a linear change with the increase of the triclosan concentration. It has high measurement accuracy, a wide measurement range, can achieve accurate measurement in the range of 1-950 mg / L, and has good selectivity, enabling specific detection of triclosan. The present invention uses a fluorescence method for determination, with high measurement stability, short response time, and can realize on-site detection, which is convenient, fast, and has low detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 is the scanning electron microscope image of the Zn 2 GeO 4 :Mn 2+ nanoparticles in step (4) of Example 1 of the present invention;

[0017] Figure 2 is the Zn in step (4) of Example 1 of the present invention 2 GeO 4 :Mn 2+ emission spectrum diagram of the nanoparticles;

[0018] Figure 3 is the Zn in step (4) of Example 1 of the present invention 2 GeO 4 :Mn 2+ nanoparticles and the Fourier transform infrared spectrum diagram of the Zn 2 GeO 4 :Mn 2+ nanoparticles modified with amino groups in step (7);

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

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

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

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

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

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

[0025] Figure 10 It is the relationship diagram 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. The excitation light source is 254 nm and the power is 8 W;

[0026] Figure 11 It is the specific test result diagram of the fluorescent composite nanomaterial prepared in Example 3 of the present invention for triclosan. Detailed implementation manners

[0027] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

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

[0029] Prepare Zn 2+ nanoparticles modified with amino groups and doped with Mn 2 GeO 4 and CuInSe 2 quantum dots modified with carboxyl groups and doped with Zn;

[0030] Mix the Zn 2+ nanoparticles modified with amino groups and doped with Mn 2 GeO 4 with the CuInSe 2 quantum dots modified with carboxyl groups and doped with Zn, triclosan, citric acid, sodium salicylate, hexamethylenetetramine and yttrium chloride in a solvent, stir and react, then centrifuge the reaction solution, take the precipitate, add a mixed solution of methanol and acetic acid, stir for a set time, and then centrifuge and wash to obtain.

[0031] In the above method of the present invention, the Zn 2+ nanoparticles modified with amino groups and doped with Mn 2GeO 4 nanoparticles and carboxyl - modified and Zn - doped CuInSe 2 quantum dots are coupled by dehydration condensation under the action of a condensing agent to form Zn 2 GeO 4 :Mn 2+ -Zn - CuInSe 2 nanoparticles. Yttrium chloride generates Y(OH) x , Y(OH) x during the formation process, which interacts with the surface of Zn 2 GeO 4 :Mn 2+ -Zn - CuInSe 2 nanoparticles (such as electrostatic attraction, chemical bonding or physical adsorption, etc.), gradually aggregates and grows on its surface, and finally forms a Y(OH) 2 GeO 4 :Mn 2+ -Zn - CuInSe 2 layer covering the Zn x GeO 2 :Mn 4 -Zn - CuInSe 2+ nanoparticles, obtaining a Zn 2 GeO x :Mn 2 -Zn - CuInSe 4 @Y(OH) 2+ fluorescent composite nanomaterial. After the formation of Zn 2 GeO 4 :Mn 2+ nanoparticles, it provides a stable structural framework for the whole system, enabling the doped Mn 2 to maintain a relatively stable state in its lattice, which is beneficial to the stability and reproducibility of the fluorescence performance. After the combination of Zn x GeO 2 :Mn 4 , Zn - CuInSe 2+ and Y(OH) x x , through their respective fluorescence characteristics and the existing energy transfer and synergy among them, can generate 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. Their combined rich fluorescence emission characteristics and various physical and chemical properties enable this fluorescent composite nanomaterial to be applicable to a wider range of detection objects and detection environments. By reasonably designing and regulating Zn 2 GeO 4 :Mn 2+ 2 and Y(OH) xIts composition, structure, and surface properties can endow it with higher selectivity and affinity for specific target substances. Combining the synergistic effects of the three enables the 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 nanomaterials of the present invention, the addition of triclosan can enable the fluorescent composite nanomaterials to form corresponding coordination (equivalent to "holes") with triclosan. Subsequently, triclosan is removed through the washing action of methanol and acetic acid, thereby forming a pore structure with a specific shape and size on the surface of the fluorescent composite nanomaterials, facilitating subsequent applications such as adsorption, separation, or detection of specific substances (triclosan).

[0033] In the present invention, the Zn 2+ GeO 2 nanoparticles modified with amino groups and doped with Mn 4 The dosage ratio of the CuInSe 2 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 the reactants and uniformly mix them, thereby promoting the reaction. The CuInSe 2 doped with Zn is dissolved in cyclohexane, and triclosan is an organic substance that is not easily soluble in water. Cyclohexane can serve as a good organic solvent to disperse triclosan evenly, enabling it to better contact and interact with other substances.

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

[0035] In the present invention, the method for preparing the Zn 2+ GeO 2 nanoparticles modified with amino groups and doped with Mn 4 is as follows:

[0036] Mix a zinc salt, a manganese salt, and dilute nitric acid, and then add Na 2 GeO 3 . Adjust the pH to 7.2 - 7.9 by adding an alkaline solution, carry out a hydrothermal synthesis reaction, and purify to obtain the Zn 2+ GeO 2 nanoparticles doped with Mn 4 ; then the Zn 2+ nanoparticles doped with Mn2 GeO 4 The GeO nanoparticles react with dopamine under alkaline conditions to obtain Zn doped with Mn and modified with amino groups 2+ GeO 2 nanoparticles; wherein, the molar ratio of zinc salt to manganese salt is (95 - 99.5):(0.5 - 5). The present invention places no special restrictions on the selection of zinc salt and manganese salt, and common zinc salts and manganese salts in the art can be used. The present invention preferably uses zinc nitrate and manganese chloride. The present invention places no special restrictions on the purification process, and common purification methods in the art can be used. The dosage ratio of the Zn doped with Mn 4 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 form 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 polymerization process of dopamine, which can not only adjust the pH but also further introduce amino groups. The present invention uses dopamine reaction to modify amino groups, which can impart unique properties and activities to the surface of the Zn doped with Mn 2+ GeO 2 nanoparticles, introduce not only amino groups but also form a special organic layer on the surface of the nanoparticles, and will not damage the internal structure of the nanoparticles, thereby maintaining the original optical, electrical and other properties of the nanoparticles. 4 GeO 2+ 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 form 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 polymerization process of dopamine, which can not only adjust the pH but also further introduce amino groups. The present invention uses dopamine reaction to modify amino groups, which can impart unique properties and activities to the surface of the Zn doped with Mn 2 GeO 4 nanoparticles, introduce not only amino groups but also form a special organic layer on the surface of the nanoparticles, and will not damage 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 CuInSe quantum dots modified with carboxyl groups and doped with Zn is as follows: 2 Under the protection of inert gas, zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene and dodecanethiol are mixed and heated for reaction, then a mixed solution of Se powder, oleylamine and dodecanethiol is added, and the reaction is continued by heating. After cooling, purification is carried out to obtain CuInSe

[0038] quantum dots doped with Zn; then the CuInSe 2 quantum dots doped with Zn are mixed and reacted with nitrous tetrafluoroborate, and then mixed and reacted with polyacrylic acid to obtain CuInSe 2 quantum dots modified with carboxyl groups and doped with Zn. 2

[0039] ​In the present invention, the inert gas is preferably nitrogen to avoid the adverse effect of the presence of oxygen on the material synthesis. The dosage ratio of zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene, Se powder, oleylamine and 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 doped Zn CuInSe 2 Quantum dots, nitrous tetrafluoroborate and polyacrylic acid have a dosage ratio of (4 - 8) mg : (180 - 220) mg : (180 - 220) mg. Nitrous tetrafluoroborate can remove surface organic ligands and activate the surface of quantum dots. Polyacrylic acid is connected to the doped Zn CuInSe 2 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 provide the lone pairs of electrons to the empty orbitals of metal ions on the surface of quantum dots to form coordination bonds. This coordination makes polyacrylic acid able to be tightly connected to the surface of the doped Zn CuInSe 2 Quantum dots to form a stable complex. When polyacrylic acid is connected to the surface of quantum dots, its abundant carboxyl groups can react with substances containing amino groups (-NH 2 ). The doped Mn 2+ modified Zn 2 GeO 4 nanoparticles) undergo dehydration condensation reactions.

[0040] In the preparation process of the doped Zn CuInSe 2 Quantum dots of the present invention, the reaction temperature for the post - mixing heating reaction is 150 - 170 °C, and the reaction time is 20 - 60 min; the reaction temperature for the subsequent heating reaction is 150 - 170 °C, and the reaction time is 10 - 30 min. The doped Zn CuInSe 2 Quantum dots are prepared by solvothermal reaction.

[0041] The present invention also provides a fluorescent composite nanomaterial for detecting triclosan prepared by the above - mentioned preparation method. The fluorescent composite nanomaterial provided by the present invention (Zn 2 GeO 4 :Mn 2+ -Zn - CuInSe 2 @Y(OH) x) It has the advantage of strong fluorescence emission. Under the excitation of a 254 nm laser, it has a green light emission peak at 525 - 540 nm, and the fluorescence intensity at the peak shows a good linear relationship with the concentration of triclosan. Therefore, it can be used for the detection of triclosan concentration.

[0042] The present invention also provides the application of the above-mentioned fluorescent composite nanomaterial for detecting triclosan in the detection of triclosan. The application method is as follows:

[0043] Mix the fluorescent composite nanomaterial for detecting triclosan with triclosan solutions of different concentrations, use a 254 nm excitation light source as the excitation light, detect the emission spectrum, and establish a standard curve according to the relationship between the fluorescence intensity and the concentration at 525 - 540 nm of the emission spectrum;

[0044] Then mix the triclosan solution to be measured with the fluorescent composite nanomaterial for detecting triclosan, use a 254 nm excitation light source as the excitation light, detect the emission spectrum, and determine the concentration of the triclosan solution to be measured according to the standard curve.

[0045] The technical solution of the present invention will be further described below in conjunction with specific embodiments. The present invention has no special restrictions on the sources of the reagents used in the following embodiments, and commercially available products well-known to those skilled in the art can be used. Room temperature in the following embodiments refers to 25 ± 3 °C.

[0046] Example 1

[0047] This example provides the preparation of Zn 2 GeO 4 :Mn 2+ (Zn 2 GeO 4 :Mn 2+ -NH 2 ) nanoparticles.

[0048] (1) Add Zn(NO 3 ) 2 (1.98 mmol) and MnCl 2 (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, then add 2 mmol of GeO 2 to it and stir to obtain a Na 2 GeO 3 solution. Take 5.5 mL of the above solution and add it to the solution in step (1) using a syringe, and stir the mixed solution for 30 minutes.

[0050] (3) Adjust the pH of the above solution to 7.58 with 1 wt% sodium hydroxide and stir for 30 minutes. Transfer it into a hydrothermal reactor and maintain at 220 °C for 16 h.

[0051] (4) The reacted solution was centrifuged at 10000 r / min for 10 min, washed with water and dried to obtain Zn 2 GeO 4 :Mn 2+ nanoparticles.

[0052] (5) After wet-milling 400 mg of Zn 2 GeO 4 :Mn 2+ nanoparticles, add 10 mL of NaOH solution, sonicate for 30 min, stir for 24 h, then centrifuge at a low speed of 3000 r / min for 10 min to remove large particles and impurities (nanoparticles in the suspension), and then centrifuge the suspension at a high speed of 12000 r / min for 15 min, collect the precipitate, wash it once with water, and then sonicate and disperse it in 20 mL of water to obtain Zn 2 GeO 4 :Mn 2+ aqueous dispersion.

[0053] (6) Adjust the pH of the Tris-HCl (tris(hydroxymethyl)aminomethane hydrochloride) buffer to 8.5, take 20 mL of the Zn 2 GeO 4 :Mn 2+ aqueous dispersion obtained in step (5), add 1.4 mL of 1 mg / mL dopamine aqueous solution, and stir and react at room temperature for 2 h.

[0054] (7) After the reaction, centrifuge the reaction solution at a low speed of 3000 r / min for 5 min to remove large particles and impurity precipitates, take the supernatant and disperse it in 350 mL of tris(hydroxymethyl)aminomethane hydrochloride with a pH of 8.5, add 1.5 mL of ethylenediamine, mix and stir in the dark for 24 h. Centrifuge at a high speed of 12000 r / min for 15 min, wash twice with water, and dry to obtain amino-modified Zn 2 GeO 4 :Mn 2+ nanoparticles.

[0055] Figure 1 This is the scanning electron microscope image of the Zn 2 GeO 4 :Mn 2+ nanoparticles in step (4) of this example. It can be seen from the figure that the nanoparticles are rod-shaped, with a particle length of 50 - 100 nm and a diameter of 20 - 40 nm.

[0056] Figure 2 Zn in step (4) of this embodiment 2 GeO 4 :Mn 2+ Emission spectrum of nanoparticles, the excitation light source used is 254 nm and the power is 8 W. It can be seen from the figure that for Zn 2 GeO 4 :Mn 2+ The emission peak of the nanoparticles is 532 nm.

[0057] Figure 3 Zn in step (4) of this embodiment 2 GeO 4 :Mn 2+ Nanoparticles and the Zn modified with amino groups in step (7) 2 GeO 4 :Mn 2+ Fourier transform infrared spectroscopy (FTIR) diagram of the nanoparticles. It can be seen from the figure that for Zn 2 GeO 4 :Mn 2+ The absorption peak of the surface functional group (-OH) is 3296 cm -1 For Zn 2 GeO 4 :Mn 2+ -NH 2 The absorption peak of the surface functional group (-OH) is 3310 cm -1 1407 cm -1 Is the absorption peak of -NH 2 The change in the position of the -OH functional group and the appearance of the -NH 2 Absorption peak indicate that the amino treatment of Zn 2 GeO 4 :Mn 2+ Is successfully achieved.

[0058] Example 2

[0059] This example provides a preparation method of carboxyl-modified and Zn-doped CuInSe 2 (Zn-CuInSe 2 -COOH) quantum dots.

[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-dodecyl mercaptan into a four-necked flask. Evacuate for 10 minutes, stir with a high-temperature magnetic stirrer, and heat to 160 °C under nitrogen and stir for 30 minutes.

[0061] (2) Dissolve 0.19 mmol of Se powder in 0.5 mL of oleylamine and 0.5 mL of 1-dodecanethiol. Inject the mixture into the four-necked flask in step (1) using a syringe, and continue stirring and reacting at 160 °C for 20 minutes. Then cool to room temperature.

[0062] (3) Add 10 ml of ethanol to the four-necked flask cooled to room temperature, and then centrifuge at a speed of 12,000 r / min for 10 minutes. Take the precipitate, add 15 mL of cyclohexane, and sonicate. Then centrifuge at 4500 r / min for 5 minutes. Take the supernatant to obtain 15 mL of a cyclohexane dispersion of Zn-CuInSe 2 (about containing 20.5 mg of Zn-CuInSe 2 ).

[0063] (4) Take a 50 mL centrifuge tube, add 6 mL of cyclohexane and 10 mL of N,N-dimethylformamide, and stir for 2 minutes; then add 200 mg of nitrosyl tetrafluoroborate and stir for 10 minutes; then add 5 mL of the cyclohexane dispersion of Zn-CuInSe 2 and stir for about 30 minutes. After stirring, irradiate with a laser. If the lower part emits light, the stirring is completed (after treatment with nitrosyl tetrafluoroborate and dispersed in DMF). If the upper part emits light, continue stirring is required. After the stirring is completed, centrifuge at a speed of 12,000 r / min for 10 minutes, take the precipitate, add 5 mL of N,N-dimethylformamide, and sonicate to disperse it evenly to obtain a N,N-dimethylformamide dispersion of Zn-CuInSe 2 .

[0064] (5) Weigh 200 mg of polyacrylic acid with a beaker, add 10 mL of N,N-dimethylformamide, sonicate, and add 5 mL of the N,N-dimethylformamide dispersion of Zn-CuInSe 2 in step (4). Stir overnight and centrifuge at a speed of 12,000 r / min for 10 minutes. Wash the precipitate once with water, and then disperse it in 20 mL of water to obtain a Zn-CuInSe 2 -COOH aqueous dispersion.

[0065] Figure 4 is the emission spectrum diagram of the Zn-CuInSe 2 quantum dots prepared in this example under an excitation light source of 365 nm and 8 W. It can be seen that the emission peak of the Zn-CuInSe 2 quantum dots is 452 nm.

[0066] Figure 5 is the transmission electron microscopy (TEM) image of the Zn-CuInSe 2 quantum dots prepared in this example, and their size is about 3 - 5 nm.

[0067] Figure 6 is the Zn-CuInSe prepared in this example 2 quantum dots and Zn-CuInSe 2 -COOH quantum dots in the Fourier transform infrared spectroscopy. It can be seen that after the reaction with polyacrylic acid, the Zn-CuInSe 2 -COOH quantum dots show an absorption peak at 1661.01 cm -1 . This peak is attributed to the carbonyl absorption peak, indicating successful modification.

[0068] Example 3

[0069] This example provides a preparation method of a fluorescent composite nanomaterial Zn 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x .

[0070] (1) Take 200 mg of the amino-modified Zn 2 GeO 4 :Mn 2+ nanoparticles in Example 1 and disperse them in 10 mL of deionized water to obtain a Zn 2 GeO 4 :Mn 2+ -NH 2 aqueous dispersion.

[0071] (2) Mix 10 mL of the Zn 2 GeO 4 :Mn 2+ -NH 2 aqueous dispersion in step (1), 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 Zn-CuInSe 2 -COOH aqueous dispersion in Example 2 at room temperature, stir for 1 h, then heat to 70 °C and stir for 7 h. Then add 10 mL of ethanol and open the lid to evaporate ethanol and cyclohexane.

[0072] (3) Centrifuge at a speed of 12000 r / min for 10 minutes to obtain the precipitate. Add 20 mL of methanol and acetic acid in a volume ratio of 9:1, stir for 24 h. Then centrifuge at a speed of 11000 r / min for 10 minutes, wash twice with water, and disperse in 5 mL of water to obtain an aqueous solution of the Zn 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x fluorescent composite nanomaterial.

[0073] Figure 7 Scanning electron micrograph of the fluorescent composite nanomaterial prepared in this example. It can be seen that the nanoparticles are spherical in shape with a size of approximately 30 - 50 nm.

[0074] Figure 8 Fourier transform infrared spectroscopy (FTIR) graph of the fluorescent composite nanomaterial prepared in this example. The absorption peaks at 3351.57 cm -1 and 1637.85 cm -1 are typical stretching vibration peaks of amide bonds, indicating the formation of amide bonds through dehydration condensation between amino and carboxyl groups.

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

[0076] Test Example

[0077] 1. Detect the concentration of triclosan using the Zn 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x fluorescent composite nanomaterial of Example 3:

[0078] (1) Prepare aqueous solutions of triclosan with different concentrations from 1 to 950 mg / L. Take 150 μL of each concentration and add it to a 1.5 mL centrifuge tube. Then add 150 μL of the aqueous solution of the Zn 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x fluorescent composite nanomaterial of Example 3 to each centrifuge tube.

[0079] (2) Under the excitation of a laser at 254 nm and 8 W, measure the emission intensity (330 - 700 nm) of the solutions in all centrifuge tubes, and obtain the linear relationship between the triclosan concentration and the emission intensity of the fluorescent composite nanomaterial at 532 nm, as Figure 10 shown. The fitted linear equation is y = -2.511x + 5801.564, and the goodness of fit R 2 = 0.989, indicating that the regression line has a good fitting degree for the measured values.

[0080] 2. Specificity test of the Zn 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x fluorescent composite nanomaterial of Example 3 for triclosan:

[0081] (1) Prepare aqueous solutions of triclocarban, triclosan, 2-bromo-nitrophenol, bisphenol A, dopamine hydrochloride, and ascorbic acid at the same concentration (850 mg / L). Take 150 μL of each and add it to a 1.5 mL centrifuge tube. Then add 150 μL of the Zn in Example 3 to each centrifuge tube. 2 GeO 4 -Zn-CuInSe 2 @Y(OH) x aqueous solution of the fluorescent composite nanomaterial.

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

[0083] (3) Under the excitation of a 254 nm, 8 W laser, measure the emission peak intensity at 532 nm of the solutions in all centrifuge tubes, and record the difference between its emission intensity and that 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 Figure 11 shown. It can be seen that the fluorescent composite nanomaterial prepared by the present invention has good detection specificity for triclosan.

[0084] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope 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-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 for reaction, and then the solution after the reaction 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.

2. The preparation method according to claim 1, characterized in that 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, characterized in that: 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 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, characterized in that: 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, perform hydrothermal synthesis reaction, and purify to obtain doped Mn 2+ Zn2GeO4 nanoparticles; then doping Mn 2+ Zn2GeO4 nanoparticles react with dopamine under alkaline conditions to obtain amino-modified and Mn-doped 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, characterized in that: 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.

6. The preparation method according to claim 1, characterized in that: 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 for reaction, 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; then the Zn-doped CuInSe2 quantum dots are mixed with nitrous tetrafluoroborate for reaction, and then mixed with polyacrylic acid for reaction, to obtain CuInSe2 quantum dots modified with carboxyl groups and doped with Zn.

7. The preparation method according to claim 6, characterized in that: The dosage ratio of zinc acetate, cuprous iodide, indium acetate, oleic acid, octadecene, Se powder, oleylamine and n-dodecyl mercaptan 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, tetrafluoroborate nitrosamine and polyacrylic acid is (4-8) mg: (180-220) mg: (180-220) mg.

8. The preparation method according to claim 6, characterized in that: 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. The 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 excitation light, the emission spectrum is detected, and a standard curve is established according to the relationship between the fluorescence intensity and the concentration at 525 to 540 nm of the emission spectrum; 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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