Composite fluorescent sensing material for detecting methylamphetamine drugs as well as preparation method and application of composite fluorescent sensing material

Abstract

The invention provides a composite fluorescent sensing material for detecting methylamphetamine drugs, and belongs to the technical field of fluorescent sensing materials and drug detection. The composite fluorescent sensing material is obtained by reacting a precursor molecule R1-FR2-R3 with a metal salt compound. The precursor molecules R1-FR2-R3 are synthesized from an organic ligand capable of being coordinated and crosslinked with metal ions, a fluorinated benzene ring containing two aldehyde groups and a recognition molecule capable of selectively adsorbing MAs and generating fluorescence quenching. The fluorescent sensing film prepared from the composite fluorescent sensing material has excellent selectivity and sensitivity when being used for detecting methylamphetamine compounds. According to the method for preparing the composite fluorescent sensing material, the morphology and size of the material can be regulated and controlled, so that a material structure which is more beneficial to enrichment of MAs molecules is selectively prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent sensing materials and the technical field of drug detection, and in particular to a composite fluorescent sensing material for detecting methamphetamine-type drugs, and a preparation method and application thereof. Background Art

[0002] Methamphetamine (MAs) compounds belong to amphetamine stimulants and are highly addictive illegal drugs, commonly known as ice. Drug abuse not only harms people's physical and mental health, but also poses a great threat to public safety and social stability. The means by which criminals carry and transport MAs are usually extremely covert, so the demand for the detection of MAs vapor molecules is increasing.

[0003] Currently developed MAs detection technologies include mass spectrometry, electrochemical method, surface enhanced Raman scattering spectroscopy, ion mobility spectrometry, colorimetric analysis, etc. These methods have the problems of large instruments, high cost and complex sample pretreatment process, which have prompted the development of new technologies for detecting MAs vapor molecules. Fluorescence technology is one of the internationally recognized new technologies for highly sensitive detection of MAs. Fluorescent film sensors are widely used in the detection of MAs vapor molecules due to their simple operation and high sensitivity.

[0004] "Efficient fluorescent vapour sensing induced by ZnO buffer" (DOI: 10.1016 / j.dyepig.2023.111420) discloses a receptor regulation strategy, which effectively captures MAs vapor molecules by substituting different numbers of fluorine atoms, and synthesizes the conjugated polymer of 4,7-dibromo-5-fluoro-2,1,3-benzothiazole by Suzuki reaction. Finally, the fluorescent sensing film is prepared by spin coating to realize the detection of MAs vapor molecules. "Trifluoromethyl-Substituted Perylene Diimides for Rapid and Sensitive Film-Based Fluorescence Detection of Methamphetamine and Cocaine Hydrochloride" (DOI: 10.1002 / adfm.202311328) synthesized fluoromethyl-substituted perylene diimide derivatives. The ionization potential of this fluorescent compound is high enough to cause photoinduced hole transfer. The fluorescent sensing film is also made by spin coating to realize sensitive sensing of MAs vapor molecules.

[0005] At present, the fluorescence sensing of MAs mainly focuses on the development of new conjugated polymers and the modification of fluorescent compounds. Other studies focus on the development of micro-nano materials with fluorescent properties, such as carbon quantum dots and their composite fluorescent materials. These methods and the above-mentioned prior art still have some problems for the fluorescence sensing of MAs, such as unsatisfactory selectivity and sensitivity. In addition, there is no research on combining micro-nano materials and fluorescent molecules for the sensing of MAs. Summary of the invention

[0006] Based on the above technical problems, the present invention provides a composite fluorescent sensing material for detecting methamphetamine drugs. The composite fluorescent sensing material is obtained by reacting a precursor molecule R1-FR2-R3 with a metal salt compound. The precursor molecule R1-FR2-R3 is synthesized from an organic ligand capable of cross-linking with metal ions, a fluorinated benzene ring containing two aldehyde groups, and a recognition molecule capable of selectively adsorbing MAs and producing fluorescence quenching.

[0007] Specifically, the present invention adopts the following technical solutions to achieve the above objectives: A composite fluorescent sensing material for detecting methamphetamine-type drugs, wherein the composite fluorescent sensing material is obtained by reacting a precursor molecule R1-FR2-R3 with a metal salt compound; the precursor molecule R1-FR2-R3 is synthesized from a methyl-containing organic ligand compound R1, a fluorinated benzene ring compound FR2 containing two aldehyde groups, and a compound R3; the structural formula of the compound R3 is as follows: ; Where R is (C n H 2n+1 ) m , n is an integer from 1 to 6, and m is 2 or 3.

[0008] The methyl-containing organic ligand compound R1 of the synthetic precursor molecule can coordinate and cross-link with specific metal ions to form a metal organic framework, the fluorinated benzene ring compound FR2 containing two aldehyde groups can enhance the adsorption selectivity of MAs molecules, and the compound R3 can selectively adsorb MAs and produce fluorescence quenching. The two aldehyde groups in the compound FR2 can undergo condensation reactions with the methyl group in the compound R1 and the alkyl group in the compound R3, respectively.

[0009] In a preferred embodiment, the methyl-containing organic ligand compound R1 is at least one of 2-methylimidazole, 2-methyl-1,4-phthalic acid, and 2-methylbenzene-1,3,5-tricarboxylic acid.

[0010] In a preferred embodiment, the structural formula of the fluorinated benzene ring compound FR2 containing two aldehyde groups is any one of the structural formulas shown in formulas (1) to (17):

[0011]

[0012]

[0013]

[0014] .

[0015] In a preferred embodiment, the metal salt compound is a compound containing Zn 2+ , Fe 3+ Cr 3+ Cr 6+ 、Co 2+ 、Zr 4+ , Cu + , Cu 2 + A metal salt compound containing at least one ion.

[0016] The present invention also provides a method for preparing the composite fluorescent sensing material, comprising the following steps: S1, synthetic precursor molecule R1-FR2-R3 The methyl-containing organic ligand compound R1 and the fluorinated benzene ring compound FR2 containing two aldehyde groups are dissolved in a first organic solvent respectively, a first alkaline catalyst is added, and the mixture is heated to reflux, and the reflux is maintained until the reaction is completed; after the reaction is completed, the mixture is rotary evaporated, and the obtained product is chromatographed on a silica column using a mixed solvent of dichloromethane and methanol to obtain compound A; Dissolve compound A and compound R3 in a second organic solvent respectively, add a second alkaline catalyst, heat to reflux, and keep reflux until the reaction is completed; after the reaction is completed, perform rotary evaporation, and chromatograph the obtained product using a mixed solvent of dichloromethane and methanol through a silica column to obtain a precursor molecule R1-FR2-R3; S2. Synthesis of composite fluorescent sensing materials The precursor molecules R1-FR2-R3 and the metal salt compound are respectively dissolved in a third solvent and reacted completely at room temperature; after the reaction, the composite fluorescent sensing material is obtained by centrifugation, washing and drying.

[0017] In a preferred embodiment, the molar ratio of the methyl-containing organic ligand compound R1, the fluorinated benzene ring compound FR2 containing two aldehyde groups, and the compound R3 in step S1 is 1:1.3:1.

[0018] In a preferred embodiment, the first alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine and piperidine.

[0019] In a preferred embodiment, the second alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine and piperidine.

[0020] In a preferred embodiment, the molar ratio of the precursor molecule R1-FR2-R3 to the metal salt compound in step S2 is (1-16):1.

[0021] The present invention also provides a fluorescent sensor film, which is obtained by coating the composite fluorescent sensor material on a substrate.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) When the fluorescent sensing film prepared by the composite fluorescent sensing material provided in the present invention is used to detect methamphetamine compounds, it can realize rapid detection of vapor molecules of methamphetamine compounds and is not interfered by other organic amine compounds. That is, the fluorescent sensing film provided by the present invention has excellent selectivity for methamphetamine compounds when the fluorescent sensing method is used to detect methamphetamine compounds.

[0023] (2) The composite fluorescent sensing material prepared by the method of the present invention can regulate the morphology and size of the composite fluorescent sensing material. The larger specific surface area of ​​the composite fluorescent sensing material can more effectively achieve the enrichment of MAs molecules.

[0024] (3) Compared with directly loading fluorescent compounds onto MOFs, the composite fluorescent sensing material provided in the present invention has a higher loading rate for fluorescent compounds and is more sensitive to the detection of MAs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a SEM image of the composite fluorescent sensing material prepared in Example 1 of the present invention; Figure 2 This is a SEM image of the composite fluorescent sensing material prepared in Example 2 of the present invention; Figure 3 This is a SEM image of the composite fluorescent sensing material prepared in Example 3 of the present invention; Figure 4 The fluorescence spectra of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 1 in Example 5 of the present invention in response to different concentrations of methamphetamine vapor; Figure 5The fluorescence spectra of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 2 in Example 5 of the present invention in response to different concentrations of methamphetamine vapor; Figure 6 The fluorescence spectra of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 3 in Example 5 of the present invention in response to different concentrations of methamphetamine vapor; Figure 7 A bar chart showing the fluorescence quenching ratio of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 1 in Example 6 of the present invention in response to different organic amine vapors; Figure 8 A bar chart showing the fluorescence quenching ratio of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 2 in Example 6 of the present invention in response to different organic amine vapors; Fig. 9 A bar chart showing the fluorescence quenching ratio of the fluorescent sensor film prepared by using the composite fluorescent sensor material prepared in Example 3 in Example 6 of the present invention in response to different organic amine vapors; Fig.10 The fluorescence spectra of the fluorescent sensing film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 1 in Comparative Example 5 in response to different concentrations of methamphetamine vapor; Fig.11 The fluorescence spectra of the fluorescent sensing film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 2 in Comparative Example 5 in response to different concentrations of methamphetamine vapor; Fig.12 The fluorescence spectra of the fluorescent sensing film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 3 in Comparative Example 5 in response to different concentrations of methamphetamine vapor. DETAILED DESCRIPTION

[0026] The following content is combined with the embodiments to clearly and completely describe the technical solution of the present application so that those skilled in the art can fully understand the present application. Obviously, the described embodiments are only some preferred embodiments of the present application, rather than all embodiments. Any equivalent transformation or substitution made to the following implementation modes by those of ordinary skill in the art without creative work belongs to the protection scope of the present application.

[0027] The specific embodiment of the present invention provides a method for preparing a composite fluorescent sensing material for detecting methamphetamine drugs, comprising the following steps: S1, synthetic precursor molecule R1-FR2-R3 The methyl-containing organic ligand compound R1 and the fluorinated benzene ring compound FR2 containing two aldehyde groups are dissolved in the first organic solvent, and the first alkaline catalyst is added, and the mixture is heated to reflux, and the reflux is maintained until the reaction is completed. After the reaction is completed, the product is subjected to rotary evaporation, and the obtained product is chromatographed on a silica column to obtain compound A, and the chromatographic eluent is a mixed solvent of dichloromethane and methanol.

[0028] Compound A and recognition molecule compound R3 are dissolved in a second organic solvent, a second alkaline catalyst is added, and the mixture is heated to reflux, and the reflux is maintained until the reaction is completed. After the reaction is completed, the product is subjected to rotary evaporation, and the obtained product is chromatographed on a silica column to obtain the precursor molecule R1-FR2-R3, and the chromatographic eluent is a mixed solvent of dichloromethane and methanol.

[0029] The structure of compound R3 is shown in Formula I: (Formula I), wherein R is (C n H 2n+1 ) m , n is an integer from 1 to 6, and m is 2 or 3.

[0030] S2. Synthesis of composite fluorescent sensing materials The precursor molecules R1-FR2-R3 and the metal salt compound are dissolved in the third solvent respectively, and the reaction is completed at room temperature. After the reaction is completed, centrifugation is performed, and the solid product is washed with the third solvent and then dried to obtain a composite fluorescent sensing material.

[0031] In a preferred embodiment, the molar ratio of the methyl-containing organic ligand compound R1, the fluorinated benzene ring compound FR2 containing two aldehyde groups, and the recognition molecule compound R3 is 1:1.3:1.

[0032] In a preferred embodiment, the methyl-containing organic ligand compound R1 is at least one of 2-methylimidazole, 2-methyl-1,4-phthalic acid, and 2-methylbenzene-1,3,5-tricarboxylic acid; 2-methylimidazole is further preferred.

[0033] In a preferred embodiment, the fluorinated benzene ring compound FR2 containing two aldehyde groups is any one of the structural formulas shown in formulas (1) to (17):

[0034]

[0035]

[0036]

[0037] .

[0038] In a further preferred embodiment, the fluorinated benzene ring compound FR2 containing two aldehyde groups is a compound represented by formula (17).

[0039] In a preferred embodiment, the first organic solvent is anhydrous ethanol.

[0040] In a preferred embodiment, the first alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine and piperidine; piperidine is further preferred, and 0.2 μL of piperidine is added to each ml of the reaction system.

[0041] In a preferred embodiment, the eluent for eluting compound A in step S1 is a mixed solvent of dichloromethane and methanol in a volume ratio of 10:1.

[0042] In a preferred embodiment, the second organic solvent is anhydrous ethanol.

[0043] In a preferred embodiment, the second alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine and piperidine; piperidine is further preferred, and 0.2 μL of piperidine is added to each ml of the reaction system.

[0044] In a preferred embodiment, the eluent for eluting the precursor molecules R1-FR2-R3 in step S1 is a mixed solvent of dichloromethane and methanol in a volume ratio of 10:1.

[0045] In a preferred embodiment, the metal salt compound in step S2 is Zn 2+ , Fe 3+ Cr 3+ Cr 6+ 、Co 2+ 、Zr 4+ , Cu + , Cu 2+ A metal salt compound of at least one metal ion.

[0046] In a preferred embodiment, the molar ratio of the precursor molecule R1-FR2-R3 to the metal salt compound is (1~16):1. For example, when the molar ratio of the precursor molecule R1-FR2-R3 to zinc nitrate is 1:1, the obtained material has a cubic shape and a size of 600nm. When the molar ratio of the precursor molecule R1-FR2-R3 to zinc nitrate is 4:1, the obtained material has a truncated rhombic dodecahedron and a size of 1μm. When the molar ratio of the precursor molecule R1-FR2-R3 to zinc nitrate is 7:1, the obtained material has a truncated rhombic dodecahedron and a size of 600nm. When the molar ratio of the precursor molecule R1-FR2-R3 to zinc nitrate is 9:1, the obtained material has a truncated rhombic dodecahedron and a size of 300nm. When the molar ratio of the precursor molecule R1-FR2-R3 to zinc nitrate is 16:1, the obtained material has a truncated rhombic dodecahedron and a size of 100nm.

[0047] In a preferred embodiment, the third solvent is methanol and / or water.

[0048] Example 1 A method for preparing a composite fluorescent sensing material for detecting methamphetamine drugs comprises the following steps: S1, synthetic precursor molecule R1-FR2-R3 82.1 mg of 2-methylimidazole and 267.9 mg of tetrafluoroterephthalaldehyde were dissolved in 100 mL of ethanol, and 20 μL of piperidine was added and refluxed, activated for 30 min, and refluxed at 80°C for 4 h. After the reaction was completed, a crude solid product was obtained by rotary evaporation, and purified by silica column chromatography using dichloromethane / methanol (the volume ratio of dichloromethane to methanol was 10:1) as the eluent to obtain compound A. The main reaction equation for the synthesis of compound A is shown in Formula II.

[0049] 351.2 mg of compound A and 728.4 mg of compound R3 were dissolved in 100 mL of ethanol, and 20 μL of piperidine was added and refluxed, activated for 30 min, and refluxed at 80 ° C for 4 h. After the reaction was completed, a crude solid product was obtained by rotary evaporation, and dichloromethane / methanol (the volume ratio of dichloromethane to methanol was 10:1) was used as the eluent and purified by silica column chromatography to obtain a precursor molecule R1-FR2-R3 containing a three-segment structure. The main reaction equation for the synthesis of the precursor molecule R1-FR2-R3 is shown in Formula III.

[0050]

[0051] .

[0052] S2. Synthesis of composite fluorescent sensing materials 31.268g of the precursor molecule R1-FR2-R3 and 0.595g of zinc nitrate hexahydrate were dissolved in 20mL of anhydrous methanol, mixed evenly and stirred at room temperature for 1h. After the reaction was completed, the mixture was centrifuged and washed with methanol. The product was collected and dried to obtain a ZIF-8 composite fluorescent sensor material. The scanning electron microscope image of the composite fluorescent sensor material synthesized in this example is shown in FIG. Figure 1 As shown, from Figure 1 It can be seen from the above that the shape of the synthesized composite fluorescent sensing material is a truncated rhombic dodecahedron with a size of 300 nm.

[0053] Example 2 A method for preparing a composite fluorescent sensing material for detecting methamphetamine drugs comprises the following steps: S1. The process of synthesizing the precursor molecule R1-FR2-R3 is the same as step S1 in Example 1.

[0054] S2. Synthesize fluorescent sensing materials 24.320g of the precursor molecule R1-FR2-R3 and 0.595g of zinc nitrate hexahydrate were dissolved in 20mL of methanol, mixed evenly and stirred at room temperature for 1h. After the reaction was completed, the mixture was centrifuged and washed with methanol. The product was collected and dried to obtain a ZIF-8 composite fluorescent sensor material. The scanning electron microscope image of the composite fluorescent sensor material synthesized in this embodiment is shown in FIG. Figure 2 As shown, from Figure 2 It can be seen from the above that the shape of the synthesized composite fluorescent sensing material is a truncated rhombic dodecahedron with a size of 600 nm.

[0055] The main chemical reaction equations in this embodiment are the same as those in Example 1 and will not be repeated here. It can be seen from the structural dimensions of the composite fluorescent sensing materials prepared in Example 1 and Example 2 that the size of the material can be regulated by preparing the MOFs composite fluorescent sensing material using the method in this application. According to the types of methyl-containing organic ligand compound R1 and metal salt compound, the prepared metal organic framework compounds (MOFs) include zeolite-imidazole framework (ZIF), Levahill organic framework (MIL), and Oslo metal organic framework (UIO); combined with different reaction conditions, the size of the prepared composite fluorescent sensing material is 100~1000nm, and the morphology is a truncated rhombic dodecahedron or a cube.

[0056] Example 3 A method for preparing a composite fluorescent sensing material for detecting methamphetamine drugs comprises the following steps: S1. The process of synthesizing the precursor molecule R1-FR2-R3 is the same as step S1 in Example 1.

[0057] S2. Synthesize fluorescent sensing materials 3.474 g of the precursor molecule R1-FR2-R3 and 0.595 g of zinc nitrate hexahydrate were dissolved in 20 mL of methanol, mixed evenly and stirred at room temperature for 1 h. After the reaction was completed, the mixture was centrifuged and washed with methanol. The product was collected and dried to obtain a ZIF-8 composite fluorescent sensor material. The scanning electron microscope image of the composite fluorescent sensor material synthesized in this example is shown in FIG. Figure 3 As shown, from Figure 3 It can be seen from the above that the synthesized composite fluorescent sensing material has a cubic shape and a size of 600 nm.

[0058] The main chemical reaction equations in this embodiment are the same as those in embodiment 1, and are not described here again. From the external structures of the composite fluorescent sensing materials prepared in embodiments 1, 2, and 3, it can be seen that the morphology of the material can be regulated by using the method in this application to prepare the composite fluorescent sensing material.

[0059] Example 4 A method for preparing a fluorescent sensor film comprises the following steps: R1. Activate the substrate: Prepare a piranha solution by mixing 30wt% hydrogen peroxide and 98wt% concentrated sulfuric acid in a volume ratio of 3:7. Wash a 13mm diameter round quartz glass slide with distilled water and ethanol in turn, dry it, and then immerse the quartz glass slide in the piranha solution. Heat the piranha solution to boiling, activate for about 30 minutes, and cool naturally to room temperature. Rinse the quartz glass slide with distilled water and ethanol in turn to remove the residual piranha solution on the surface, and then blow it dry with nitrogen.

[0060] R2. The composite fluorescent sensing materials prepared in Examples 1 to 3 were dissolved in xylene, and the concentration of the composite fluorescent sensing material in each solution was 5 mg / mL. 40 μL of each solution was added dropwise onto the activated quartz glass slide. The spin coater parameters were set to a speed of 2000 rpm, a spin coating time of 30 seconds, and then dried at 50°C for 1 hour under a pressure of 3000 Pa in a vacuum drying oven, taken out, and sealed for storage to prepare a fluorescent sensing film.

[0061] Those skilled in the art will appreciate that a quartz waveguide may be used to replace the quartz glass slide to prepare the fluorescent sensor film.

[0062] Example 5 In this embodiment, a fluorescent sensing film is used to detect methamphetamine compounds, and the specific method is as follows: Each fluorescent sensor film prepared in Example 4 was placed in a quartz cuvette with four sides transparent to light, and the quartz cuvette was sealed with a cover. The quartz cuvette was placed in a fluorescence spectrometer with an excitation wavelength of 465 nm and an angle of 40° between the incident light and the fluorescent sensor film. The fluorescence emission intensity was recorded as the reference value I0, i.e., the initial fluorescence emission intensity of the fluorescent sensor film without methamphetamine molecules.

[0063] Add 1 μL of methamphetamine ethanol solution with concentrations of 0 ng / μL, 1 ng / μL, 10 ng / μL, and 100 ng / μL to each quartz cuvette in turn. When adding the sample, avoid direct contact between the solution and the fluorescent sensor film, and then cover and seal the quartz cuvette. Heat the quartz cuvette to 60°C for 60 seconds to allow the sample to completely evaporate. Place the quartz cuvette in a fluorescence spectrometer with an excitation wavelength of 465 nm and an angle of 40° between the incident light and the fluorescent sensor film, and measure its fluorescence emission intensity I (the fluorescence spectra are shown in the following diagrams). Figures 4 to 6 The fluorescence intensity quenching ratio caused by the vapor generated by the volatilization of the sample can be calculated by the following formula:

[0064] Where PL Q is the fluorescence intensity quenching ratio of the fluorescent sensor film caused by the vapor generated by the volatilization of the sample; I0 is the reference value (the fluorescence emission intensity when no sample is added to the quartz cuvette), and I is the fluorescence emission intensity after the vapor generated by the volatilization of the sample contacts the fluorescent sensor film.

[0065] from Figure 4 It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite fluorescent sensor material prepared in Example 1 is located at 606nm, and the reference value I0 is 4627. The I value after the ethanol solution evaporates is 3726, and the I values ​​after the 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions evaporate are 2681, 2597, and 2447, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions is Q They are 29.2%, 42.1%, 43.9% and 47.1% respectively.

[0066] from Figure 5It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite fluorescent sensor material prepared in Example 2 is located at 606nm, and the reference value I0 is 4710. The I value after the ethanol solution evaporates is 3357, and the I values ​​after the 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions evaporate are 2042, 908, and 689, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions is Q They are 28.7%, 56.7%, 80.7% and 85.4% respectively.

[0067] from Figure 6 It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite fluorescent sensor material prepared in Example 3 is located at 606nm, and the reference value I0 is 4413. The I value after the ethanol solution evaporates is 3692, and the I values ​​after the 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions evaporate are 3448, 2984, and 2719, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL methamphetamine ethanol solutions is Q They are 16.3%, 21.9%, 32.4% and 38.4% respectively.

[0068] Example 6 This example studies the selectivity of the fluorescent sensing film prepared in Example 4, and the specific method is as follows: The I0 value of each fluorescent sensor film prepared in Example 4 was determined according to the method in Example 5. The different fluorescent sensor films prepared in Example 4 were placed in a quartz cuvette with four sides transparent to light, and 1 μL of diisopropylamine ethanol solution, monoisopropylamine ethanol solution, aniline ethanol solution, and triethylamine ethanol solution with a concentration of 100 ng / μL were added to each of them. When adding the sample, avoid direct contact between the solution and the fluorescent sensor film, and then cover and seal the quartz cuvette. Heat the quartz cuvette to 60°C for 60 seconds to allow the sample to completely evaporate. Place the quartz cuvette in a fluorescence spectrometer with an excitation wavelength of 465nm and an angle of 40° between the incident light and the fluorescent sensor film. Measure its fluorescence emission intensity I, and calculate PL according to the formula in Example 5. Q Different fluorescence sensing films detect the fluorescence intensity quenching ratio (PL Q ) are shown in the bar graphs Figures 7-9 shown.

[0069] from Figure 7It can be seen from the above that when the fluorescent sensing film prepared by the composite fluorescent sensing material prepared in Example 1 is used to detect diisopropylamine, monoisopropylamine, triethylamine, aniline and N-isopropylbenzylamine, the fluorescence quenching ratios are 20.6%, 15.3%, 8.5%, 12.3% and 17.6%, respectively.

[0070] from Figure 8 It can be seen from the above that when the fluorescent sensing film prepared by the composite fluorescent sensing material prepared in Example 2 is used to detect diisopropylamine, monoisopropylamine, triethylamine, aniline and N-isopropylbenzylamine, the fluorescence quenching ratios are 22.4%, 16.6%, 10.1%, 11.9% and 20.1%, respectively.

[0071] from Fig. 9 It can be seen from the above that when the fluorescent sensing film prepared by the composite fluorescent sensing material prepared in Example 3 is used to detect diisopropylamine, monoisopropylamine, triethylamine, aniline and N-isopropylbenzylamine, the fluorescence quenching ratios are 15.1%, 11%, 5.7%, 7.9% and 13.4%, respectively.

[0072] from Figures 7-9 It can be seen from the above that, under the same sample concentration, no matter which fluorescent sensor film in Example 4 is used, the fluorescence quenching ratio caused by methamphetamine is much higher than that of other organic amine compounds. This shows that the fluorescent sensor film prepared by the composite fluorescent sensor material prepared in this application has significant selectivity for methamphetamine compounds.

[0073] Comparative Example 1 A method for preparing a composite material of ZIF-8 loaded with a fluorescent compound comprises the following steps: S1. Synthesize fluorescent compound FR2-R3 0.268 g of tetrafluoroterephthalaldehyde and 0.728 g of compound R3 were dissolved in 100 mL of ethanol, and 20 μL of piperidine was added and refluxed, activated for 30 min, and refluxed at 80 ° C for 4 h. After the reaction was completed, a crude solid product was obtained by rotary evaporation, and dichloromethane / methanol (the volume ratio of dichloromethane to methanol was 10:1) was used as the eluent, and purified by silica column chromatography to obtain fluorescent compound FR2-R3. The main reaction equation for the synthesis of fluorescent compound FR2-R3 is shown in Formula IV.

[0074]

[0075] S2. Synthesis of MOF-loaded composite materials with fluorescent compounds 1.478g 2-methylimidazole, 0.595g zinc nitrate hexahydrate and 26.653g fluorescent compound FR2-R3 were dissolved in 20mL methanol solution respectively, stirred at room temperature for 1h after mixing. Centrifugal reaction was performed, and washed with methanol, and product was collected and dried to obtain a composite material of ZIF-8 loaded fluorescent compound. The size and shape of the composite material of ZIF-8 loaded fluorescent compound synthesized in this comparative example are the same as those in Example 1, and the outer shape is a truncated rhombic dodecahedron with a size of 300nm.

[0076] Comparative Example 2 A method for preparing a composite material of ZIF-8 loaded with a fluorescent compound comprises the following steps: S1. The process of synthesizing the fluorescent compound FR2-R3 is the same as step S1 in comparative example 1.

[0077] S2. Synthesis of MOF-loaded composite materials with fluorescent compounds 1.149g 2-methylimidazole, 0.595g zinc nitrate hexahydrate and 20.730g fluorescent compound FR2-R3 were dissolved in 20mL methanol solution respectively, stirred at room temperature for 1h after mixing. Centrifugal reaction was performed, and washed with methanol, and product was collected and dried to obtain the composite material of ZIF-8 loaded fluorescent compound. The size and shape of the composite material of ZIF-8 loaded fluorescent compound synthesized in this comparative example are the same as those in Example 2, and the outer shape is a truncated rhombic dodecahedron with a size of 600nm.

[0078] Comparative Example 3 A method for preparing a composite material of ZIF-8 loaded with a fluorescent compound comprises the following steps: S1. The process of synthesizing the fluorescent compound FR2-R3 is the same as step S1 in comparative example 1.

[0079] S2. Synthesis of MOF-loaded composite materials with fluorescent compounds 0.164g 2-methylimidazole, 0.595g zinc nitrate hexahydrate and 20.730g fluorescent compound FR2-R3 are dissolved in 20mL methanol solution respectively, stirred at room temperature for 1h after mixing. Centrifugal after reaction is completed, and washed with methanol, product is collected, dried, and the composite material of ZIF-8 loaded fluorescent compound is obtained. The size and morphology of the composite material of ZIF-8 loaded fluorescent compound synthesized in this comparative example are the same as those in Example 3, and the outer shape is a cube with a size of 600nm.

[0080] Comparative Example 4 The composite fluorescent sensing materials prepared in Examples 1 to 3 in step R2 of Example 4 were replaced with the composite materials of ZIF-8 loaded with fluorescent compounds prepared in Comparative Examples 1 to 3, respectively, to prepare three fluorescent sensing films.

[0081] Comparative Example 5 According to the same method as in Example 5, the methamphetamine compounds were detected using the fluorescent sensing films prepared in Comparative Example 4. The obtained fluorescence spectra are as follows: Figures 10-12 shown.

[0082] from Fig.10 It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 1 is located at 606nm, and the reference value I0 is 1962. The I value after ethanol volatilization is 1750, and the I values ​​after 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution volatilization are 1745, 1734, and 1705, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution is Q They are 10.8%, 11.1%, 11.6% and 13.1% respectively. It can be seen that when the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 1 is used to detect methamphetamine, the fluorescence intensity quenching ratio produced is not much improved compared with anhydrous ethanol, and the detection of methamphetamine cannot be achieved.

[0083] from Fig.11 It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 2 is located at 606nm, and the reference value I0 is 2681. After ethanol volatilization, the I value is 2447, and the I values ​​of 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution after volatilization are 2424, 2433, and 2157, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution is Q They are 8.7%, 9.3%, 9.6% and 19.5% respectively. It can be seen that when the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 2 is used to detect methamphetamine, the concentration of methamphetamine needs to be high enough (detection limit is 100 ng / μL) to be clearly distinguished from the fluorescence intensity quenching ratio produced by anhydrous ethanol.

[0084] from Fig.12It can be seen from the figure that the emission wavelength of the fluorescent sensor film prepared by the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 3 is located at 606nm, and the reference value I0 is 1819. The I value after ethanol volatilization is 1764, and the I values ​​after 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution volatilization are 1764, 1749, and 1611, respectively. After calculation, the fluorescence intensity quenching ratio PL caused by the volatilization of ethanol and 1ng / μL, 10ng / μL, and 100ng / μL of methamphetamine ethanol solution is Q 3%, 3%, 3.8% and 11.4% respectively. It can be seen that when the composite material of ZIF-8 loaded with fluorescent compound prepared in Comparative Example 3 is used to detect methamphetamine, the concentration of methamphetamine needs to be high enough (detection limit is 100 ng / μL) to be clearly distinguished from the fluorescence intensity quenching ratio produced by anhydrous ethanol.

[0085] In summary, the sensitivity of the fluorescent sensing film prepared by the composite fluorescent sensing material provided in the present application to detect methamphetamine is much higher than that of the fluorescent sensing film prepared by the composite material of ZIF-8 loaded with fluorescent compounds prepared in the comparative example. This is mainly because the preparation method in the present application can achieve a higher loading amount of fluorescent compounds.

[0086] The above-described embodiments are only preferred embodiments of the present application and are not intended to limit the scope of protection of the present application. For any person skilled in the art, the present application may have various changes and modifications. Any simple equivalent changes and modifications made based on the scope of protection of the present application and the contents of the specification should be included in the scope of protection of the present application.

Claims

1. A composite fluorescent sensing material for detecting methamphetamine drugs, characterized in that: The composite fluorescent sensing material is obtained by reacting a precursor molecule R1-FR2-R3 with a metal salt compound; the precursor molecule R1-FR2-R3 is synthesized from a methyl-containing organic ligand compound R1, a fluorinated benzene ring compound FR2 containing two aldehyde groups, and a compound R3; the structural formula of the compound R3 is as follows: ； Where R is (C n H 2n+1 ) m , n is an integer from 1 to 6, and m is 2 or 3.

2. The composite fluorescent sensing material according to claim 1, characterized in that: The methyl-containing organic ligand compound R1 is at least one of 2-methylimidazole, 2-methyl-1,4-phthalic acid, and 2-methylbenzene-1,3,5-tricarboxylic acid.

3. The composite fluorescent sensing material according to claim 1, characterized in that: The structural formula of the fluorinated benzene ring compound FR2 containing two aldehyde groups is any one of the structural formulas shown in formulas (1) to (17): 。 4. The composite fluorescent sensing material according to claim 1, characterized in that: The metal salt compound contains Zn 2 + , Fe 3+ Cr 3+ Cr 6+ 、Co 2+ 、Zr 4+ , Cu + , Cu 2+ A metal salt compound containing at least one ion.

5. The method for preparing the composite fluorescent sensing material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, synthetic precursor molecule R1-FR2-R3 The methyl-containing organic ligand compound R1 and the fluorinated benzene ring compound FR2 containing two aldehyde groups are dissolved in a first organic solvent respectively, a first alkaline catalyst is added, and the mixture is heated to reflux, and the reflux is maintained until the reaction is completed; after the reaction is completed, the mixture is rotary evaporated, and the obtained product is chromatographed on a silica column using a mixed solvent of dichloromethane and methanol to obtain compound A; Dissolve compound A and compound R3 in a second organic solvent respectively, add a second alkaline catalyst, heat to reflux, and keep reflux until the reaction is completed; after the reaction is completed, perform rotary evaporation, and chromatograph the obtained product using a mixed solvent of dichloromethane and methanol through a silica column to obtain a precursor molecule R1-FR2-R3; S2. Synthesis of composite fluorescent sensing materials The precursor molecules R1-FR2-R3 and the metal salt compound are respectively dissolved in a third solvent and reacted completely at room temperature; after the reaction, the composite fluorescent sensing material is obtained by centrifugation, washing and drying.

6. The method for preparing the composite fluorescent sensing material according to claim 5, characterized in that: The molar ratio of the methyl-containing organic ligand compound R1, the fluorinated benzene ring compound FR2 containing two aldehyde groups, and the compound R3 is 1:1.3:1; or / and the molar ratio of the precursor molecule R1-FR2-R3 and the metal salt compound is (1~16):

1.

7. The method for preparing the composite fluorescent sensing material according to claim 5, characterized in that: The first alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, and piperidine; or / and the second alkaline catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propylenediamine, 1,2-propylenediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, and piperidine.

8. A fluorescent sensing film, characterized in that: The fluorescent sensing film is obtained by coating the composite fluorescent sensing material according to any one of claims 1 to 4 on a substrate.

9. Use of the composite fluorescent sensing material according to any one of claims 1 to 4 in detecting methamphetamine drugs.

10. Use of the fluorescent sensor film according to claim 8 in detecting methamphetamine drugs.

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