Up-conversion composite nano-material for detecting triclosan as well as preparation method and application of up-conversion composite nano-material

Abstract

The invention discloses an up-conversion composite nanomaterial for detecting triclosan as well as a preparation method and application of the up-conversion composite nanomaterial, and belongs to the technical field of triclosan detection. The up-conversion composite nanomaterial provided by the invention comprises carbon dots, up-conversion nanoparticles and ruthenium salt, the upconversion nanoparticle is of a core-shell structure, a NaYF4: Yb < 3 + > / Er < 3 + > nanoparticle is taken as an inner core, and the surface of the inner core is coated with a NaYF4: Eu < 3 + > shell layer; the carbon dots and the up-conversion nanoparticles are connected through amido bonds. The up-conversion composite nanomaterial provided by the invention is relatively low in cost, relatively simple in preparation method, relatively high in fluorescence emission intensity, capable of being used for detecting the concentration of triclosan, simple, convenient and rapid in detection mode, low in instrument cost and capable of realizing on-site detection and real-time monitoring at the same time.

Description

Technical Field

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

[0002] The information disclosed in the background of the invention is only intended to enhance the understanding of the overall background of the invention and should not be necessarily regarded as an acknowledgment 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 may also cause environmental pollution, so it is necessary to monitor triclosan in the environment.

[0004] Traditional triclosan detection methods include high performance liquid chromatography, gas chromatography-mass spectrometry, etc., 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 up-conversion composite nanomaterial for detecting triclosan, and 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, wherein NaYF 4 :Yb 3+ / Er 3+ The nanoparticles are the core, and NaYF is coated on the surface of the core. 4 :Eu 3+ Shell; the carbon dots and the upconversion nanoparticles are connected by amide bonds; the mass ratio of the carbon dots to the upconversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and the upconversion nanoparticles is about 1.5-2.0; 3+ The dosage ratio is (50~100) mg:0.02 mmol.

[0007] Preferably, the NaYF 4 :Yb 3+ / Er 3+In nanoparticles, Yb 3+ The doping concentration is 15-25 mol%, Er 3+ The doping concentration of NaYF is 1 to 3 mol%; 4 :Eu 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] NaYF was prepared by solvothermal method. 4 :Yb 3+ / Er 3+ Nanoparticles as the core, NaYF 4 :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 a 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 mixing with NaYF 4 :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.

[0011] Furthermore, the NaYF 4 :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, and the mixture is heated and mixed and then a solvent thermal reaction is performed to obtain the nanoparticles.

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

[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 for reaction, to obtain 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 up-conversion composite nanomaterial is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm is used as the 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 440 to 460 nm of the emission spectrum;

[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 up-conversion composite nanomaterial provided by the present invention has low cost and a relatively simple preparation method. It has a high fluorescence emission intensity. 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 concentration of triclosan can be detected by a 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 constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute an improper limitation of the present invention. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[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, and the excitation light source used is 980nm;

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

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

[0026] Figure 5 This is a scanning electron microscope image 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 365nm;

[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 UCNPs-NH prepared in Example 1 of the present invention 2 and Fourier infrared absorption spectra of UCNPs-CDs and CDs prepared in Example 2;

[0030] Fig. 9 UCNPs-CDs-Ru prepared in Example 2 of the present invention 3+ SEM images of the samples, the scale bar is 100 nm;

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

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

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

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

[0035] Fig.14The 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] Fig.15 The triclosan solutions of different concentrations in Application Example 1 of the present invention and the UCNPs-CDs-Ru in Example 2 3+ The relationship between the peak emission intensity at 450nm after mixing, the excitation light source used is 365nm;

[0037] Fig.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 are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0039] The invention provides an upconversion composite nanomaterial for detecting triclosan, comprising carbon dots, upconversion nanoparticles and ruthenium salts; the upconversion nanoparticles are core-shell structures, and NaYF 4 :Yb 3+ / Er 3+ The nanoparticles are the core, and NaYF is coated on the surface of the core. 4 :Eu 3+ Shell; the carbon dots and the upconversion nanoparticles are connected by amide bonds; the mass ratio of the carbon dots to the upconversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and the upconversion nanoparticles is about 1.5-2.0; 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] It is particularly important that the upconversion nanoparticles (UCNPs) of the present invention adopt a core-shell structure, which is composed of NaYF 4 :Yb 3+ / Er 3+ As the core, NaYF 4 :Eu 3+ As a shell layer. This core-shell structure can not only further improve the NaYF 4 :Yb 3+ / Er 3+ The emission fluorescence intensity can be increased, and the particle size of the upconversion nanoparticles can be increased. After the particle size is increased, the attachment sites with CDs, ruthenium salts and triclosan are increased, which helps to form a more stable composite system and strengthen the correlation between the change of fluorescence signal and the concentration of triclosan; on the other hand, it expands the detection range of triclosan, improves the sensitivity and accuracy of the detection, and makes the method of detecting triclosan concentration using the upconversion composite nanomaterial more efficient and reliable.

[0043] In the present invention, the NaYF 4 :Yb 3+ / Er 3+ In nanoparticles, Yb 3+ The doping concentration is 15-25 mol%, Er 3+ The doping concentration of NaYF is 1 to 3 mol%; 4 :Eu 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 finally formed upconversion composite nanomaterial is 30-35 nm.

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

[0046] NaYF was prepared by solvothermal method. 4 :Yb 3+ / Er 3+ Nanoparticles as the core, NaYF 4 :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 a 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 mixing with NaYF 4 :Yb 3+ / Er 3+ Nanoparticles, sodium hydroxide and ammonium fluoride are mixed, heated and mixed, and then subjected to solvent thermal reaction to obtain the product. The present invention does not impose any special restrictions on the types of ytterbium salts and europium salts, and the ytterbium salts and europium salts commonly used in the art can be used. The present invention does not impose any special restrictions on the specific conditions of the above reaction, and the product can be obtained by using means commonly used in the art. The specific amount of addition depends on the designed ratio.

[0048] The NaYF of the present invention 4 :Yb 3+ / Er 3+ The preparation method of 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, and after heating and mixing, a solvent thermal reaction is carried out to obtain the nanoparticles. The present invention does not impose any special restrictions on the types of ytterbium salt, erbium salt and yttrium salt, and the commonly used ytterbium salt, erbium salt and yttrium salt in the art can be used. The present invention does not impose any special restrictions on the specific conditions of the above reaction, and the nanoparticles can be obtained by using the commonly used means in the art. The specific amount of addition depends on the designed ratio.

[0049] In the present invention, the method for modifying the amino groups on the surface of the upconversion nanoparticles is: after the upconversion nanoparticles react with nitroso tetrafluoroborate, they are mixed with polyethyleneimine for reaction, so as to obtain the upconversion nanoparticles with the amino groups modified on the surface. The principle of preparing the upconversion nanoparticles with the amino groups modified on the surface by this method is: first, nitroso tetrafluoroborate reacts with the upconversion nanoparticles, and uses its oxidizing property and coordination ability to act on the active sites on the surface of the nanoparticles to activate them, and may also introduce new functional groups such as nitroso. Then, polyethyleneimine contains a large number of amino groups and has nucleophilicity, and can react with the electrophilic groups on the surface of the nanoparticles after the nitroso tetrafluoroborate treatment to undergo nucleophilic reaction, and there are also electrostatic effects and hydrogen bonding between the two, so that the polyethyleneimine is connected to the surface of the nanoparticles to achieve amino modification.

[0050] The present invention does not impose any special restrictions on the preparation process of carbon dots, and the surface thereof contains a large number of carboxyl groups, which can be used to undergo a dehydration condensation reaction with upconversion nanoparticles modified with amino groups for connection. In the present invention, 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 for reaction, and obtaining upconversion nanoparticle-carbon dot materials. The present invention does not impose any special restrictions on the specific conditions of the reaction, and the conditions for the dehydration condensation reaction commonly used in the art can be used.

[0051] In the present invention, 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. This step is to fully combine the ruthenium ions with the upconversion nanoparticle-carbon dot material. The present invention does not impose any special restrictions on the ruthenium salt, and commonly used ruthenium salts can be selected, such as ruthenium chloride.

[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 up-conversion composite nanomaterial is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm is used as the 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 440 to 460 nm of the emission spectrum;

[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 in conjunction with specific examples. The present invention has no particular limitation on the source 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 an upconversion nanoparticle (UCNPs-NH 2 ) preparation method.

[0059] 1. Preparation of NaYF by solvothermal method 4 :Yb 3+ / Er 3+ Nanoparticles:

[0060] (1) Add YCl into a three-necked flask3 6H 2 O (0.78 mmol, 78%), YbCl 3 6H 2 O (0.2mmol, 20%), ErCl 3 6H 2 O (0.02mmol, 2%), and heated to 90°C, stirred and evaporated to dryness.

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

[0062] (3) Lower the temperature to room temperature (below 40°C), weigh NaOH (0.1 g), NH 4 F (0.1482 g) was 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 closed environment; and stirred and heated to 300° C. 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 solution after the reaction (i.e., the solution obtained in step (4)), and centrifuge at 10000 r / min × 10 min to obtain NaYF 4 :Yb 3+ / Er 3+ Upconversion nanoparticles (about 205 mg).

[0065] (6) NaYF obtained in step (5) 4 :Yb 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 NaYF 4 :Yb 3+ / Er 3+ Nuclear solution.

[0066] 2. Preparation of NaYF by Solvothermal Method 4 :Yb 3+ / Er 3+ @NaYF 4 :Eu 3+ :

[0067] (1) Add YCl into a three-necked flask 3 6H 2 O (0.78 mmol, 78%), YbCl3 6H 2 O (0.2mmol, 20%), ErCl 3 6H 2 O (0.02mmol, 2%), and heated to 90°C, stirred and evaporated to dryness.

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

[0069] (3) The temperature was lowered to room temperature (below 40°C), and the core solution (i.e., NaYF 4 :Yb 3+ / Er 3+ The solution was added into the reaction solution of step (2), the mixed solution was heated to 70° C. and maintained for 30 min, and the cyclohexane was removed.

[0070] (4) Lower the temperature to room temperature (below 40°C), weigh NaOH (0.1 g), NH 4 F (0.1482 g) was 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 closed environment; and stirred and heated to 300° C. 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 solution after the reaction (i.e., the solution obtained in step (5)), and centrifuge at 10000 r / min × 10 min to obtain NaYF 4 :Yb 3+ / Er 3+ @NaYF 4 :Eu 3+ Upconversion nanoparticles (about 400 mg).

[0073] (7) NaYF obtained in step (6) 4 :Yb 3+ / Er 3+ @NaYF 4 :Eu 3+ 10 mL of cyclohexane was added to the upconversion nanoparticles, and the supernatant was collected at 4500 r / min for 5 min to obtain NaYF 4 :Yb 3+ / Er 3+ @NaYF 4 :Eu 3+ Solution.

[0074] 3. Preparation of UCNPs-NH 2 :

[0075] (1) Weigh 50 mg of nitroso tetrafluoroborate (NOBF 4 ), pour it into a centrifuge tube, add 5 mL of dimethylformamide (DMF) and 2 mL of cyclohexane and stir for 10 min.

[0076] (2) Take 5 mL of NaYF from step 2 4 :Yb 3+ / Er 3+ @NaYF 4 :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 DMF.

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

[0078] (4) The solution obtained in step (2) and step (3) was 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-NH 2 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 nanoparticles are in a cake shape.

[0080] Figure 2 This is the emission spectrum of the surface-modified amino 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 drop 11.98 mL of ethanolamine (0.2 mol) aqueous solution into the citric acid aqueous solution and stir vigorously until the solution is clear.

[0085] (2) Seal the above clarified solution in a reaction kettle, heat it to 180 °C and maintain for 6 h, and then naturally cool it to room temperature to obtain a red-brown liquid.

[0086] (3) Add the red-brown liquid into a dialysis bag with a molecular weight cut-off of 3500 for dialysis, change the water every 4 h, and dialyze for three days to remove excessive small-molecule products and impurities, obtaining a purified aqueous solution of CDs.

[0087] Figure 3 This is the transmission electron microscopy image of the CDs prepared in this example, and their size is 3 - 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 material:

[0090] (1) Weigh 20 mg of EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and 10 mg of NHS (N-hydroxysuccinimide), put them into a centrifuge tube, add 10 mL of water, and ultrasonically dissolve it; then add 10 mL of aqueous CDs solution (containing about 245 mg of CDs) and stir for 2 h (activating carboxyl groups).

[0091] (2) Take 5 mL of the UCNPs-NH 2 aqueous dispersion (containing about 40 mg of UCNPs) in Example 1 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 it in 20 mL of water to finally obtain the UCNPs-CDs material.

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

[0093] Figure 6 This is the emission spectrum of the 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 the 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 This is the UCNPs-NH prepared in Example 1 2The Fourier transform infrared absorption spectra (FTIR) of UCNPs-CDs and CDs prepared in this example are shown in Figure 1. As can be seen from the figure, the absorption peaks of the functional groups on the surface of CDs are 1646 cm -1 、1400cm -1 、2950nm,UCNPs-NH 2 The absorption peaks of the surface functional groups are 1644 cm -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 NaYF 4 :Yb 3+ / Er 3+ @NaYF 4 :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 (containing about 71 mg of UCNPs-CDs) from step 2 into a centrifuge tube and add 20 mL of 1 mmol / L RuCl 3 The solution was stirred overnight.

[0098] (2) The resulting 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] Fig. 9 UCNPs-CDs-Ru prepared in this example 3+ Scanning electron microscopy (SEM) images of UCNPs-CDs-Ru 3+ The nanoparticles are in the shape of cakes, with a particle size of about 30 to 35 nm.

[0100] Fig.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] Fig.11 UCNPs-CDs-Ru prepared in this example 3+ Emission spectrum, the excitation light source used is 365nm, and the emission peak corresponds to 456nm.

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

[0103] Fig.13 UCNPs-NH prepared in Example 1 2 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-NH 2 Completely consistent with the standard card (PDF#16-0334), UCNPs-NH appeared after loading CDs 2 The diffraction peaks of both and CDs indicate that the two have been combined; 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 the concentration of triclosan, and the specific steps are as follows:

[0106] (1) Prepare triclosan solutions of different concentrations; then 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 is excited by a laser with a wavelength of 365 nm, and the fluorescence emission spectrum at 420-475 nm is measured. Fig.14 As shown, a fitting curve was made for the concentration of triclosan solution according to the fluorescence intensity of the emission peak at 450 nm, as shown in FIG. Fig.15 As shown, the linear relationship of the obtained fitting curve is: y = 5836.201-1.130x, R 2 It is 0.93485, which has a better 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) Test 0.2 mL of UCNPs-CDs-Ru under 365 nm laser excitation 3+ Emission intensity of the dispersion (500 nm).

[0112] (3) Under 365nm laser excitation, the emission intensity (500nm) of all 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] Fig.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 above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An up-conversion composite nanomaterial for detecting triclosan, characterized in that: The invention comprises carbon dots, upconversion nanoparticles and ruthenium salts; the upconversion nanoparticles are core-shell structures, and the upconversion nanoparticles are NaYF4:Yb 3+ / Er 3+ The nanoparticles are the core, and NaYF4:Eu is coated on the surface of the core. 3+ Shell; the carbon dots and the upconversion nanoparticles are connected by amide bonds; the mass ratio of the carbon dots to the upconversion nanoparticles is (200-300): (30-50); the total mass of the carbon dots and the upconversion nanoparticles is about 1.5-2.0; 3+ The dosage ratio is (50~100) mg:0.02 mmol.

2. The up-conversion composite nanomaterial according to claim 1, characterized in that: 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 3+ In the shell, Eu 3+ The doping concentration is 3 to 7 mol%.

3. The method for preparing the up-conversion composite nanomaterial for detecting triclosan according to any one of claims 1 to 2, characterized in that: The steps include: NaYF4:Yb 3+ / Er 3+ Nanoparticles as the core, 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 a ruthenium salt are stirred in a solvent for a set time to obtain the material.

4. The preparation method according to claim 1, characterized in that: 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, characterized in that: 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, and the mixture is heated and mixed and then a solvent thermal reaction is performed to obtain the nanoparticles.

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

7. The preparation method according to claim 3, characterized in that: 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 obtaining the upconversion nanoparticle-carbon dot material.

8. The preparation method according to claim 3, characterized in that: 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.

9. Use of the up-conversion composite nanomaterial according to any one of claims 1 to 2 or the up-conversion composite nanomaterial prepared by the preparation method according to any one of claims 3 to 8 in detecting triclosan.

10. The use according to claim 9, characterized in that The specific method of the application is: The up-conversion composite nanomaterial is mixed with triclosan solutions of different concentrations, an excitation light source with a wavelength of 365 nm is used as the 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 440 to 460 nm of the emission spectrum; 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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