An upconversion composite nanomaterial for detecting triclosan, and its preparation method and application

Abstract

The present invention discloses an upconversion composite nanomaterial for detecting triclosan, its preparation method and application, and belongs to the technical field of triclosan detection. The upconversion composite nanomaterial provided by the present invention comprises carbon dots, upconversion nanoparticles and ruthenium salt; the upconversion nanoparticles are core-shell structures, which are NaYF4:Yb 3+ / Er 3+ The nanoparticles are the core, and the surface of the core is coated with NaYF4:Eu 3+ The carbon dots and upconversion nanoparticles are connected via an amide bond. The upconversion composite nanomaterial provided by the present invention is low-cost, has a relatively simple preparation method, and exhibits high fluorescence emission intensity. It can be used to detect triclosan concentration in a simple, convenient, and low-cost manner, while enabling on-site detection and real-time monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of triclosan detection, and in particular to an up-conversion composite nanomaterial for detecting triclosan, a preparation method thereof, and applications 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 broad-spectrum antibacterial agent that was once widely used, but studies have found that it may interfere with human hormone levels and pose potential hazards to health, such as causing intestinal flora imbalance and destroying liver integrity. It can also cause environmental pollution. Therefore, it is necessary to monitor triclosan in the environment.

[0004] Traditional triclosan detection methods include high-performance liquid chromatography and gas chromatography-mass spectrometry, which have the advantage of high accuracy, but have disadvantages such as expensive instruments, complex operations, cumbersome sample pretreatment, and long detection time. They are difficult to meet the needs of rapid on-site detection and real-time monitoring. Therefore, it is necessary to develop a method for rapid, simple, low-cost, highly sensitive, and highly selective detection of triclosan. Summary of the Invention

[0005] In view of this, the present invention provides an upconversion composite nanomaterial for detecting triclosan, a preparation method and application thereof, which solves the problems of long triclosan detection time, complex operation and complicated sample pretreatment in the prior art, and the luminescent composite nanomaterial has good stability.

[0006] In the first aspect, the present invention provides an upconversion composite nanomaterial for detecting triclosan, comprising carbon dots, upconversion nanoparticles and ruthenium salts; the upconversion nanoparticles are core-shell structures, which are NaYF4:Yb 3+ / Er 3+ The nanoparticles are the core, and the surface of the core is coated with NaYF4:Eu 3+ Shell; the carbon dots and up-conversion nanoparticles are connected by amide bonds; the mass ratio of the carbon dots to the up-conversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and up-conversion nanoparticles is about 100% by weight. 3+ The dosage ratio is (50~100) mg:0.02 mmol.

[0007] Preferably, the NaYF4:Yb 3+ / Er 3+ In nanoparticles, Yb 3+The doping concentration is 15-25 mol%, Er 3+ The doping concentration of NaYF4:Eu is 1 to 3 mol%; 3+ In the shell, Eu 3+ The doping concentration is 3 to 7 mol%.

[0008] In a second aspect, the present invention provides a method for preparing the above-mentioned upconversion composite nanomaterial for detecting triclosan, comprising the following steps:

[0009] NaYF4:Yb was prepared by solvothermal method. 3+ / Er 3+ Nanoparticles as the core, with NaYF4:Eu 3+ The invention discloses an upconversion nanoparticle with a shell layer, wherein amino groups are modified on the surface of the upconversion nanoparticle; then the upconversion nanoparticle with amino groups modified on the surface and carbon dots are subjected to a dehydration condensation reaction to obtain an upconversion nanoparticle-carbon dot material; finally, the upconversion nanoparticle-carbon dot material and ruthenium salt are stirred in a solvent for a set time to obtain the material.

[0010] Preferably, the preparation method of the upconversion nanoparticles comprises the following steps: heating and mixing ytterbium salt, europium salt, oleic acid and 1-octadecene under an inert atmosphere to obtain a mixed reaction solution, and then 3+ / Er 3+ The nanoparticles, sodium hydroxide and ammonium fluoride are mixed, heated and mixed, and then subjected to solvent thermal reaction to obtain the product.

[0011] Furthermore, the NaYF4:Yb 3+ / Er 3+ The preparation method of the nanoparticles is as follows: ytterbium salt, erbium salt, yttrium salt, oleic acid and 1-octadecene are heated and mixed under an inert atmosphere to obtain a mixed reaction liquid, and then sodium hydroxide and ammonium fluoride are added, heated and mixed, and then a solvent thermal reaction is carried out to obtain the nanoparticles.

[0012] Preferably, the method for modifying the surface of the upconversion nanoparticles with amino groups is: reacting the upconversion nanoparticles with nitrosotetrafluoroborate, and then mixing and reacting with polyethyleneimine to obtain upconversion nanoparticles with surface modified amino groups.

[0013] Preferably, the dehydration condensation reaction is specifically as follows: adding carbon dots to a mixed aqueous solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stirring to activate the carboxyl groups, and then adding the upconversion nanoparticles, stirring to react, and thus obtaining the upconversion nanoparticle-carbon dot material.

[0014] Preferably, in the step of stirring the upconversion nanoparticle-carbon dot material and the ruthenium salt in a solvent for a set time, the solvent is water, and the stirring time is 8 to 20 hours.

[0015] In a third aspect, the present invention provides the use of the above-mentioned upconversion composite nanomaterial or the upconversion composite nanomaterial prepared by the above-mentioned preparation method in the detection of triclosan.

[0016] Preferably, the specific method of the application is:

[0017] The upconversion composite nanomaterial was mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm was used as the excitation light, the emission spectrum was detected, and a standard curve was established based on the relationship between the fluorescence intensity at 440-460 nm of the emission spectrum and the concentration;

[0018] Then, the triclosan solution to be tested is mixed with the up-conversion composite nanomaterial, an excitation light source with a wavelength of 365 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.

[0019] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0020] The upconversion composite nanomaterial provided by the present invention has low cost and a relatively simple preparation method. It has high fluorescence emission intensity, and the emission spectrum emission peak fluorescence intensity at an excitation wavelength of 365 nm shows a good linear relationship with the triclosan concentration. Therefore, the triclosan concentration can be detected by fluorescence method. The detection method is simple, convenient and fast, and the detection instrument cost is low. At the same time, on-site detection and real-time monitoring can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 This is a scanning electron microscope (SEM) image of the upconversion nanoparticles with surface modified amino groups prepared in Example 1 of the present invention, with a scale of 100 nm;

[0023] Figure 2 This is the emission spectrum of the surface-modified amino-group upconversion nanoparticles prepared in Example 1 of the present invention, with an excitation light source of 980 nm;

[0024] Figure 3 This is a transmission electron micrograph of CDs prepared in Example 2 of the present invention, with a scale of 100 nm;

[0025] Figure 4This is the emission spectrum of CDs prepared in Example 2 of the present invention, with an excitation light source of 365 nm;

[0026] Figure 5 This is a scanning electron micrograph of the UCNPs-CDs material prepared in Example 2 of the present invention, with a scale of 100 nm;

[0027] Figure 6 This is the emission spectrum of the UCNPs-CDs material prepared in Example 2 of the present invention, and the excitation light source used is 365 nm;

[0028] Figure 7 This is the emission spectrum of the UCNPs-CDs material prepared in Example 2 of the present invention, and the excitation light source used is 980nm;

[0029] Figure 8 Fourier infrared absorption spectra of UCNPs-NH2 prepared in Example 1 and UCNPs-CDs and CDs prepared in Example 2 of the present invention;

[0030] Figure 9 UCNPs-CDs-Ru prepared in Example 2 of the present invention 3+ Scanning electron microscopy images, scale bar is 100 nm;

[0031] Figure 10 UCNPs-CDs-Ru prepared in Example 2 of the present invention 3+ Elemental analysis diagram;

[0032] Figure 11 UCNPs-CDs-Ru prepared in Example 2 of the present invention 3+ Emission spectrum of , the excitation light source used is 365nm;

[0033] Figure 12 UCNPs-CDs-Ru prepared in Example 2 of the present invention 3+ Emission spectrum of , the excitation light source used is 980nm;

[0034] Figure 13 The UCNPs-NH2 prepared in Example 1 of the present invention and the UCNPs-CDs and UCNPs-CDs-Ru prepared in Example 2 3+ X-ray diffraction pattern of

[0035] Figure 14 The concentration of triclosan in the application example 1 of the present invention is 600mg / L-1000mg / L and UCNPs-CDs-Ru 3+ Emission spectrum of , the excitation light source used is 365nm;

[0036] Figure 15The triclosan solution of different concentrations in Application Example 1 of the present invention and the UCNPs-CDs-Ru of Example 2 3+ The relationship between the peak emission intensity at 450nm after mixing, the excitation light source used is 365nm;

[0037] Figure 16 UCNPs-CDs-Ru prepared in Example 2 of Application Example 2 of the present invention 3+ Figure 2. Triclosan-specific detection chart. DETAILED DESCRIPTION

[0038] 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.

[0039] The present invention provides an up-conversion composite nanomaterial for detecting triclosan, comprising carbon dots, up-conversion nanoparticles and ruthenium salts; the up-conversion nanoparticles are core-shell structures, and the up-conversion nanoparticles are NaYF4:Yb 3+ / Er 3+ The nanoparticles are the core, and the surface of the core is coated with NaYF4:Eu 3+ Shell; the carbon dots and up-conversion nanoparticles are connected by amide bonds; the mass ratio of the carbon dots to the up-conversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and up-conversion nanoparticles is about 100% by weight. 3+ The dosage ratio is (50~100) mg:0.02 mmol.

[0040] The up-conversion composite nanomaterial for detecting triclosan of the present invention has a blue light emission peak in the wavelength range of 440 to 500 nm under an excitation wavelength of 365 nm; and has a blue light emission peak in the wavelength range of 425 to 475 nm and a green light emission peak in the wavelength range of 500 to 575 nm under an excitation wavelength of 980 nm.

[0041] The up-conversion composite nanomaterial of the present invention has a unique principle in detecting triclosan concentration, wherein Ru 3+ The Ru 3+ The fluorescence of CDs is enhanced. 3+ There is a stronger affinity between it and triclosan. After adding triclosan, triclosan-Ru will be generated. 3+ complex, causing Ru 3+ Dissociation from the CDs surface leads to a decrease in CDs luminescence. Based on this characteristic, the triclosan concentration can be determined by detecting the fluorescence intensity.

[0042] The key point is that the upconversion nanoparticles (UCNPs) of the present invention adopt a core-shell structure, which is composed of NaYF4:Yb 3+ / Er 3+ As the core, NaYF4:Eu 3+ As a shell. This core-shell structure can not only further improve the NaYF4:Yb 3+ / Er 3+ The increased fluorescence intensity of the upconversion nanoparticles can also increase their size. This increased particle size provides more attachment sites for CDs, ruthenium salts, and triclosan. This not only helps form a more stable composite system and strengthens the correlation between fluorescence signal changes and triclosan concentration, but also expands the detection range of triclosan, improving detection sensitivity and accuracy, making the method for detecting triclosan concentration using this upconversion composite nanomaterial more efficient and reliable.

[0043] In the present invention, the NaYF4:Yb 3+ / Er 3+ In nanoparticles, Yb 3+ The doping concentration is 15-25 mol%, Er 3+ The doping concentration of NaYF4:Eu is 1 to 3 mol%; 3+ In the shell, Eu 3+ The doping concentration is 3 to 7 mol%.

[0044] In the present invention, the particle size of the upconversion nanoparticles is 25-30 nm, the particle size of the carbon dots is 3-5 nm, and the particle size of the ultimately formed upconversion composite nanomaterial is 30-35 nm.

[0045] The present invention also provides a method for preparing the above-mentioned upconversion composite nanomaterial for detecting triclosan, comprising the following steps:

[0046] NaYF4:Yb was prepared by solvothermal method. 3+ / Er 3+ Nanoparticles as the core, with NaYF4:Eu 3+ The invention discloses an upconversion nanoparticle with a shell layer, wherein amino groups are modified on the surface of the upconversion nanoparticle; then the upconversion nanoparticle with amino groups modified on the surface and carbon dots are subjected to a dehydration condensation reaction to obtain an upconversion nanoparticle-carbon dot material; finally, the upconversion nanoparticle-carbon dot material and ruthenium salt are stirred in a solvent for a set time to obtain the material.

[0047] In the present invention, the preparation method of the upconversion nanoparticles comprises the following steps: heating and mixing ytterbium salt, europium salt, oleic acid and 1-octadecene in an inert atmosphere to obtain a mixed reaction solution, and then 3+ / Er 3+Nanoparticles, sodium hydroxide, and ammonium fluoride are mixed, heated, and then subjected to a solvothermal reaction to obtain the product. The present invention does not impose any particular restrictions on the types of ytterbium and europium salts; commonly used ytterbium and europium salts in the art can be used. The present invention also does not impose any particular restrictions on the specific conditions of the above reaction; commonly used methods in the art can be used to obtain the product. The specific amount added depends on the designed ratio.

[0048] The NaYF4:Yb 3+ / Er 3+ The nanoparticles are prepared as follows: Under an inert atmosphere, ytterbium salt, erbium salt, yttrium salt, oleic acid, and 1-octadecene are heated and mixed to obtain a mixed reaction solution, followed by the addition of sodium hydroxide and ammonium fluoride. After heating and mixing, a solvothermal reaction is carried out to obtain the nanoparticles. The present invention does not impose any particular restrictions on the types of ytterbium salt, erbium salt, and yttrium salt; commonly used ytterbium salts, erbium salts, and yttrium salts in the art can be used. The present invention also does not impose any particular restrictions on the specific reaction conditions; commonly used methods in the art can be used to obtain the nanoparticles. The specific amount added depends on the designed ratio.

[0049] In the present invention, the method for modifying the surface of upconversion nanoparticles with amino groups comprises reacting the upconversion nanoparticles with nitrosotetrafluoroborate and then mixing and reacting them with polyethyleneimine to produce surface-modified amino-group upconversion nanoparticles. The principle behind this method for preparing surface-modified amino-group upconversion nanoparticles is as follows: first, nitrosotetrafluoroborate reacts with the upconversion nanoparticles, utilizing its oxidizing and coordination properties to interact with active sites on the nanoparticle surface, activating them and potentially introducing new functional groups such as nitroso groups. Then, polyethyleneimine, which contains a large number of amino groups and exhibits nucleophilic properties, undergoes a nucleophilic reaction with the electrophilic groups on the surface of the nanoparticles treated with nitrosotetrafluoroborate. Furthermore, electrostatic interactions and hydrogen bonding occur between the two, allowing the polyethyleneimine to attach to the nanoparticle surface, achieving amino group modification.

[0050] The present invention imposes no particular restrictions on the preparation process of carbon dots. Their surfaces contain a large number of carboxyl groups, which can then be used to connect with amino-modified upconversion nanoparticles through a dehydration condensation reaction. In the present invention, the dehydration condensation reaction specifically involves adding carbon dots to a mixed aqueous solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stirring to activate the carboxyl groups, then adding the upconversion nanoparticles and stirring to react, thereby obtaining an upconversion nanoparticle-carbon dot material. The present invention also imposes no particular restrictions on the specific reaction conditions; commonly used dehydration condensation reaction conditions in the art can be employed.

[0051] In the present invention, the step of stirring the upconversion nanoparticle-carbon dot material and the ruthenium salt in a solvent for a set time is performed in water, and the stirring time is 8 to 20 hours. This step is to ensure that the ruthenium ions fully bind to the upconversion nanoparticle-carbon dot material. The present invention does not impose any particular limitation on the ruthenium salt; commonly used ruthenium salts, such as ruthenium chloride, can be used.

[0052] The present invention also provides the use of the above-mentioned up-conversion composite nanomaterial or the up-conversion composite nanomaterial prepared by the above-mentioned preparation method in detecting triclosan.

[0053] In the present invention, the specific method of the application is:

[0054] The upconversion composite nanomaterial was mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm was used as the excitation light, the emission spectrum was detected, and a standard curve was established based on the relationship between the fluorescence intensity at 440-460 nm of the emission spectrum and the concentration;

[0055] Then, the triclosan solution to be tested is mixed with the up-conversion composite nanomaterial, an excitation light source with a wavelength of 365 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.

[0056] 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.

[0057] Example 1

[0058] This embodiment provides a method for preparing upconversion nanoparticles (UCNPs-NH2) with surface modified amino groups.

[0059] 1. Preparation of NaYF4:Yb by Solvothermal Method 3+ / Er 3+ Nanoparticles:

[0060] (1) Add YCl3·6H2O (0.78 mmol, 78%), YbCl3·6H2O (0.2 mmol, 20%), and ErCl3·6H2O (0.02 mmol, 2%) into a three-necked flask, heat to 90°C, stir, and evaporate to dryness.

[0061] (2) When the mixture is completely evaporated to dryness, add oleic acid (6 mL) and octadecene (15 mL) and heat to 130°C. Stir until the mixture is completely dissolved to form a light yellow transparent liquid.

[0062] (3) The temperature was lowered to room temperature (below 40°C), NaOH (0.1 g) and NH4F (0.1482 g) were weighed and dissolved in 8 mL of methanol solution, and this solution was added to the above solution (i.e., the solution obtained in step (2)). The mixed solution was heated to 70°C and maintained for 30 min, and the methanol was removed.

[0063] (4) The solution obtained in step (3) was evacuated and placed in a sealed environment; and heated to 300° C. with stirring under nitrogen protection and maintained for 1 h, and then the solution was naturally cooled to room temperature.

[0064] (5) Add excess ethanol (40 mL) to the reaction solution (i.e., the solution obtained in step (4)), and centrifuge at 10000 r / min × 10 min to obtain NaYF4:Yb 3+ / Er 3+ Upconversion nanoparticles (approximately 205 mg).

[0065] (6) NaYF4:Yb obtained in step (5) 3+ / Er 3+ Add 10 mL of cyclohexane to the upconversion nanoparticles and centrifuge at 4500 r / min for 5 min to collect the supernatant, which is the required NaYF4:Yb 3+ / Er 3+ Nuclear solution.

[0066] 2. Preparation of NaYF4:Yb by Solvothermal Method 3+ / Er 3+ @NaYF4:Eu 3+ :

[0067] (1) Add YCl3·6H2O (0.78 mmol, 78%), YbCl3·6H2O (0.2 mmol, 20%), and ErCl3·6H2O (0.02 mmol, 2%) into a three-necked flask, heat to 90°C, stir, and evaporate to dryness.

[0068] (2) When the mixture is completely evaporated to dryness, add oleic acid (6 mL) and octadecene (15 mL) and heat to 130°C. Stir until the mixture is completely dissolved to form a light yellow transparent liquid.

[0069] (3) Lower the temperature to room temperature (below 40°C) and add the core solution obtained in step 1 (i.e., NaYF4:Yb 3+ / Er 3+ The mixture was heated to 70° C. and maintained at 70° C. for 30 min, and the cyclohexane was removed.

[0070] (4) The temperature was lowered to room temperature (below 40°C), NaOH (0.1 g) and NH4F (0.1482 g) were weighed and dissolved in 8 mL of methanol solution, and this solution was added to the above solution (i.e., the solution obtained in step (3)). The mixed solution was heated to 70°C and maintained for 30 min, and the methanol was removed.

[0071] (5) The solution obtained in step (4) was evacuated and placed in a sealed environment; and heated to 300° C. with stirring under nitrogen protection and maintained for 1 h, and then the solution was naturally cooled to room temperature.

[0072] (6) Add excess ethanol (40 mL) to the reaction solution (i.e., the solution obtained in step (5)), and centrifuge at 10000 r / min × 10 min to obtain NaYF4:Yb 3+ / Er 3+ @NaYF4:Eu 3+ Upconversion nanoparticles (approximately 400 mg).

[0073] (7) NaYF4:Yb obtained in step (6) 3+ / Er 3+ @NaYF4:Eu 3+ 10 mL of cyclohexane was added to the upconversion nanoparticles, and the supernatant was collected at a speed of 4500 r / min for 5 min to obtain NaYF4:Yb 3+ / Er 3+ @NaYF4:Eu 3+ solution.

[0074] 3. Preparation of UCNPs-NH2:

[0075] (1) Weigh 50 mg of nitrosotetrafluoroborate (NOBF4), pour it into a centrifuge tube, add 5 mL of dimethylformamide (DMF) and 2 mL of cyclohexane, and stir for 10 minutes.

[0076] (2) Take 5mL of NaYF4:Yb 3+ / Er 3+ @NaYF4:Eu 3+ The solution was added to the solution obtained in step (1), stirred for 30 min, centrifuged at 12000 r / min for 10 min, the supernatant was discarded, and the precipitate was dispersed in 5 mL of DMF.

[0077] (3) Take 100 mg of polyethyleneimine (PEI) and add 10 mL of DMF. Ultrasonicate for about 5 minutes until it is completely dissolved.

[0078] (4) The solutions obtained in step (2) and step (3) were mixed and stirred overnight; then centrifuged at a speed of 12000 r / min for 15 min, washed twice with water at the same speed, and finally dispersed in 25 mL of water to finally obtain UCNPs-NH2 material.

[0079] Figure 1 This is a scanning electron microscope (SEM) image of the upconversion nanoparticles with surface modified amino groups prepared in this example. The scale is 100 nm, and the particles appear to be in a cake shape.

[0080] Figure 2 This is the emission spectrum of the surface-modified amino-group upconversion nanoparticles prepared in this example. The excitation light source used is 980 nm, and the emission peaks correspond to 448 nm, 526 nm, 545 nm, and 662 nm, respectively.

[0081] Example 2

[0082] This embodiment provides a UCNPs-CDs-Ru 3+ Material preparation method.

[0083] 1. Preparation of CDs:

[0084] (1) Weigh 19.212 g of citric acid into a beaker, add 20 mL of water and stir evenly to obtain a citric acid (0.1 mol) aqueous solution. Then, add 11.98 mL of ethanolamine (0.2 mol) aqueous solution dropwise into the citric acid aqueous solution and stir vigorously until the solution is clear.

[0085] (2) The clear solution was sealed in a reactor, heated to 180°C and maintained for 6 h, and then naturally cooled to room temperature to obtain a reddish-brown liquid.

[0086] (3) The reddish-brown liquid was added to a dialysis bag with a molecular weight cut-off of 3500 for dialysis. The water was changed every 4 hours for three days to remove excess small molecule products and impurities to obtain a purified CDs aqueous solution.

[0087] Figure 3 This is a transmission electron microscopy image of the CDs prepared in this example, and its size is 3 to 5 nm.

[0088] Figure 4 This is the emission spectrum of the CDs prepared in this example. The excitation light source used is 365 nm and the emission peak is 455 nm.

[0089] 2. Preparation of UCNPs-CDs materials:

[0090] (1) Weigh 20 mg of EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and 10 mg of NHS (N-hydroxysuccinimide), place them in a centrifuge tube, add 10 mL of water, and sonicate to dissolve them; then add 10 mL of CDs aqueous solution (containing approximately 245 mg of CDs) and stir for 2 h (to activate the carboxyl groups).

[0091] (2) Take 5 mL of the UCNPs-NH2 aqueous dispersion in Example 1 (containing approximately 40 mg of UCNPs) and add it to the solution obtained in step (1), stir for 12 h; then centrifuge at a speed of 12000 r / min for 15 min, wash twice with water at the same speed, and finally disperse in 20 mL of water to finally obtain UCNPs-CDs material.

[0092] Figure 5 This is a scanning electron microscope (SEM) image of the UCNPs-CDs prepared in this example. The UCNPs-CDs nanoparticles are in the shape of a cake, and the scale is 100 nm.

[0093] Figure 6 This is the emission spectrum of UCNPs-CDs prepared in this example. The excitation light source used is 365 nm, and the emission peak corresponds to 454 nm.

[0094] Figure 7 This is the emission spectrum of UCNPs-CDs prepared in this example. The excitation light source used is 980 nm, and the emission peaks correspond to 448 nm, 526 nm, 545 nm, and 662 nm, respectively.

[0095] Figure 8 The Fourier transform infrared absorption spectra (FTIR) of UCNPs-NH2 prepared in Example 1 and UCNPs-CDs and CDs prepared in this example are shown in the figure. As can be seen from the figure, the absorption peaks of the surface functional groups of CDs are 1646 cm -1 , 1400cm -1 , 2950nm, and the absorption peaks of the surface functional groups of UCNPs-NH2 are 1644cm -1 3500cm -1 The absorption peak of the surface functional groups of UCNPs-CDs is 1654 cm -1 、1240cm -1 , 1654cm -1 The absorption peak at 1240 cm corresponds to the stretching vibration of the OH bond in the hydroxyl group -OH. -1 The absorption peak at is related to the bending vibration of the amide bond. The existence of the amide bond indicates that NaYF4:Yb 3+ / Er 3+ @NaYF4:Eu 3+It is combined with CDs through dehydration condensation between amino and carboxyl groups.

[0096] 3. UCNPs-CDs-Ru 3+ Preparation of materials:

[0097] (1) Pour 5 mL of the UCNPs-CDs solution from step 2 (containing approximately 71 mg of UCNPs-CDs) into a centrifuge tube, then add 20 mL of 1 mmol / L RuCl3 solution and stir overnight.

[0098] (2) The obtained solution was centrifuged at a speed of 12000 r / min for 10 min and washed once with water at the same speed to obtain UCNPs-CDs-Ru 3+ materials, and then the obtained UCNPs-CDs-Ru 3+ The material was dispersed in 5 mL of water to obtain UCNPs-CDs-Ru 3+ dispersion.

[0099] Figure 9 UCNPs-CDs-Ru prepared in this example 3+ Scanning electron microscopy (SEM) images of UCNPs-CDs-Ru 3+ The nanoparticles are cake-shaped and have a particle size of about 30 to 35 nm.

[0100] Figure 10 UCNPs-CDs-Ru prepared in this example 3+ Elemental analysis chart; it can be seen that it contains C, F, Na, Yb, Eu, Er, and Ru elements.

[0101] Figure 11 UCNPs-CDs-Ru prepared in this example 3+ The emission spectrum of the product is shown in Figure 2. The excitation light source used is 365 nm and the emission peak corresponds to 456 nm.

[0102] Figure 12 UCNPs-CDs-Ru prepared in this example 3+ The emission spectrum of the 20 nm excitation light source is 980 nm, and the emission peaks correspond to 448 nm, 528 nm, and 546 nm respectively.

[0103] Figure 13 The UCNPs-NH2 prepared in Example 1 and the UCNPs-CDs and UCNPs-CDs-Ru prepared in this example 3+From the X-ray diffraction pattern, it can be seen that UCNPs-NH2 is completely consistent with the standard card (PDF#16-0334). After loading CDs, the diffraction peaks of both UCNPs-NH2 and CDs appear, indicating that the two have been combined together. 3+ Does not affect the X-ray diffraction pattern.

[0104] Application Example 1

[0105] The UCNPs-CDs-Ru in Example 2 3+ The materials are used to detect triclosan concentration, and the specific steps are as follows:

[0106] (1) Prepare triclosan solutions of different concentrations; take several 1.5 mL centrifuge tubes and add 100 μL of UCNPs-CDs-Ru prepared in Example 2 to each tube. 3+ The dispersion and 100 μL of prepared triclosan solution of different concentrations (600-1000 mg / L) were mixed evenly.

[0107] (2) The sample obtained in step 1 was excited by a laser with a wavelength of 365 nm, and the fluorescence emission spectrum at 420-475 nm was measured. Figure 14 As shown in FIG, a fitting curve was made based on the fluorescence intensity of the emission peak at 450 nm and the concentration of the triclosan solution, as shown in FIG. Figure 15 As shown, the linear relationship of the fitting curve is: y = 5836.201-1.130x, R 2 It is 0.93485, which has a good degree of linearity.

[0108] Application Example 2

[0109] The UCNPs-CDs-Ru obtained in Example 2 3+ Materials undergo specific testing:

[0110] (1) Prepare solutions of ethanol, 4-hydroxybenzoic acid, ascorbic acid, triclocarban, triclosan, bisphenol A, and dopamine hydrochloride at the same concentration (700 nmol / L), take 0.2 mL of each and add them to a 1.5 mL centrifuge tube, and then add 0.2 mL of UCNPs-CDs-Ru to each centrifuge tube. 3+ Upconversion composite nanomaterials hybrid.

[0111] (2) Under 365nm laser excitation, 0.2mL of UCNPs-CDs-Ru was tested 3+ Emission intensity of the dispersion (500 nm).

[0112] (3) Under 365nm laser excitation, the emission intensity (500nm) of all the solutions in the centrifuge tubes was tested and the emission intensity of the solutions was recorded. 3+The difference in emission intensity is the emission intensity of the solution minus the emission intensity of UCNPs-CDs.

[0113] Figure 16 UCNPs-CDs-Ru obtained in Example 3 3+ The triclosan specific detection diagram of upconversion composite nanomaterials shows that only when UCNPs-CDs-Ru 3+ When the upconversion composite nanomaterial reacts with triclosan, the luminescence intensity decreases, showing good specificity.

[0114] 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. An upconversion composite nanomaterial for detecting triclosan, characterized in that: It includes carbon dots, up-conversion nanoparticles and ruthenium salts; the up-conversion nanoparticles are core-shell structures, which are NaYF4:Yb 3+ / Er 3+ The nanoparticles are the core, and the surface of the core is coated with NaYF4:Eu 3+ Shell; the carbon dots and up-conversion nanoparticles are connected by an amide bond; the mass ratio of the carbon dots to the up-conversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and up-conversion nanoparticles is Ru 3+ The dosage ratio is (50~100) mg: 0.02 mmol; The preparation method of the up-conversion composite nanomaterial for detecting triclosan comprises the following steps: preparing NaYF4:Yb 3+ / Er 3+ Nanoparticles as the core, with NaYF4:Eu 3+ The invention provides an upconversion nanoparticle with a shell layer, wherein amino groups are modified on the surface of the upconversion nanoparticle; the upconversion nanoparticle with the amino groups modified on the surface and carbon dots are subjected to a dehydration condensation reaction to obtain an upconversion nanoparticle-carbon dot material; and finally, the upconversion nanoparticle-carbon dot material and a ruthenium salt are stirred in a solvent for a set time to obtain an upconversion nanoparticle; In the step of stirring the upconversion nanoparticle-carbon dot material and the ruthenium salt in a solvent for a set time, the solvent is water and the stirring time is 8 to 20 hours; The carbon dots have carboxyl groups on their surfaces.

2. The upconversion composite nanomaterial according to claim 1, wherein The NaYF4:Yb 3+ / Er 3+ In nanoparticles, Yb 3+ The doping concentration is 15~25mol%, Er 3+ The doping concentration of NaYF4:Eu is 1~3mol%; 3+ In the shell, Eu 3+ The doping concentration is 3~7mol%.

3. The method for preparing an up-conversion composite nanomaterial for detecting triclosan according to any one of claims 1 to 2, wherein: The steps include: NaYF4:Yb was prepared by solvothermal method. 3+ / Er 3+ Nanoparticles as the core, with NaYF4:Eu 3+ The invention provides an upconversion nanoparticle with a shell layer, wherein amino groups are modified on the surface of the upconversion nanoparticle; the upconversion nanoparticle with the amino groups modified on the surface and carbon dots are subjected to a dehydration condensation reaction to obtain an upconversion nanoparticle-carbon dot material; and finally, the upconversion nanoparticle-carbon dot material and a ruthenium salt are stirred in a solvent for a set time to obtain an upconversion nanoparticle; In the step of stirring the upconversion nanoparticle-carbon dot material and the ruthenium salt in a solvent for a set time, the solvent is water and the stirring time is 8 to 20 hours.

4. The preparation method according to claim 3, wherein The preparation method of the upconversion nanoparticles comprises the following steps: heating and mixing ytterbium salt, europium salt, oleic acid and 1-octadecene in an inert atmosphere to obtain a mixed reaction solution, and then mixing with NaYF4:Yb 3+ / Er 3+ The nanoparticles, sodium hydroxide and ammonium fluoride are mixed, heated and mixed, and then subjected to solvent thermal reaction to obtain the product.

5. The preparation method according to claim 4, wherein The NaYF4:Yb 3+ / Er 3+ The preparation method of the nanoparticles is as follows: ytterbium salt, erbium salt, yttrium salt, oleic acid and 1-octadecene are heated and mixed under an inert atmosphere to obtain a mixed reaction liquid, and then sodium hydroxide and ammonium fluoride are added, heated and mixed, and then a solvent thermal reaction is carried out to obtain the nanoparticles.

6. The preparation method according to claim 3, wherein The method for modifying the surface of the upconversion nanoparticles with amino groups is as follows: reacting the upconversion nanoparticles with nitrosotetrafluoroborate, and then mixing and reacting with polyethyleneimine to obtain the upconversion nanoparticles with surface modified amino groups.

7. The preparation method according to claim 3, wherein The dehydration condensation reaction is specifically as follows: carbon dots are added to a mixed aqueous solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stirred to activate the carboxyl groups, and then the upconversion nanoparticles are added and stirred for reaction to obtain the upconversion nanoparticle-carbon dot material.

8. Use of the upconversion composite nanomaterial according to any one of claims 1 to 2 or the upconversion composite nanomaterial prepared by the preparation method according to any one of claims 3 to 7 in the detection of triclosan.

9. The use according to claim 8, characterized in that The specific method of the application is: The upconversion composite nanomaterial was mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm was used as the excitation light, the emission spectrum was detected, and a standard curve was established based on the relationship between the fluorescence intensity at 440-460 nm of the emission spectrum and the concentration; Then, the triclosan solution to be tested is mixed with the up-conversion composite nanomaterial, an excitation light source with a wavelength of 365 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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