A composite fluorescent sensing material for detecting methamphetamine and a preparation method and application thereof

Abstract

The application provides a composite fluorescent sensing material for detecting methamphetamine, and belongs to the technical fields 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 molecule R1-FR2-R3 is synthesized from an organic ligand capable of coordinating and 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. When a fluorescent sensing film prepared by using the composite fluorescent sensing material is used for detecting methamphetamine compounds, the fluorescent sensing film has excellent selectivity and sensitivity. The method for preparing the composite fluorescent sensing material in the application can control the morphology and size of the material, so that a material structure more conducive to enriching MAs molecules can be selected and prepared.

Description

TECHNICAL FIELD

[0001] The present application 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 drugs and a preparation method and application thereof. BACKGROUND

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

[0003] Currently developed MAs detection technologies include mass spectrometry, electrochemistry, surface-enhanced Raman scattering spectroscopy, ion mobility spectrometry, colorimetric analysis, etc. These methods have problems such as large instruments, high cost, and complex sample pretreatment processes, 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, and fluorescent film sensors are widely used in MAs vapor molecule detection application scenarios due to their simple operation and high sensitivity.

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

[0005] Currently, the fluorescence sensing of MAs mainly focuses on the development of new conjugated polymers and the modification of fluorescent compounds, and some other researches focus on the development of micro-nano materials with fluorescence properties, such as carbon quantum dots and their composite fluorescent materials. These methods and the existing technologies for the fluorescence sensing of MAs still have some problems, such as the unsatisfactory selectivity and sensitivity. In addition, there is no research on the combination of micro-nano materials and fluorescent molecules for the sensing of MAs. SUMMARY

[0006] Based on the above technical problems, the present application 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 coordinating and 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 application adopts the following technical solutions to achieve the above-mentioned purposes:

[0008] 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 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:

[0009] ;

[0010] wherein R is (C n H 2n+1 ) m , n is an integer from 1 to 6, and m is 2 or 3.

[0011] The methyl-containing organic ligand compound R1 of the synthesized 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.

[0012] In a preferred scheme, the methyl-containing organic ligand compound R1 is at least one of 2-methyl imidazole, 2-methyl-1,4-benzenedicarboxylic acid, and 2-methylbenzene-1,3,5-tricarboxylic acid.

[0013] In a preferred embodiment, the fluorinated benzene ring compound FR2 containing two aldehyde groups has a structure represented by any one of formulae (1) to (17):

[0014]

[0015]

[0016]

[0017]

[0018] .

[0019] In a preferred embodiment, the metal salt compound is a metal salt compound containing at least one ion of Zn 2+ , Fe 3+ , Cr 3+ , Cr 6+ , Co 2+ , Zr 4+ , Cu + , Cu 2 + .

[0020] The present application also provides a preparation method of the composite fluorescent sensing material, comprising the following steps:

[0021] S1, synthesizing a precursor molecule R1-FR2-R3

[0022] The organic ligand compound R1 containing a methyl group and the fluorinated benzene ring compound FR2 containing two aldehyde groups are respectively dissolved in a first organic solvent, a first basic catalyst is added, and heating is performed to reflux, and reflux is maintained until the reaction is completed; after the reaction is completed, rotary evaporation is performed, and the obtained product is subjected to chromatography on a silica column using a mixed solvent of dichloromethane and methanol to obtain compound A;

[0023] Compound A and compound R3 are respectively dissolved in a second organic solvent, a second basic catalyst is added, and heating is performed to reflux, and reflux is maintained until the reaction is completed; after the reaction is completed, rotary evaporation is performed, and the obtained product is subjected to chromatography on a silica column using a mixed solvent of dichloromethane and methanol to obtain the precursor molecule R1-FR2-R3;

[0024] S2, synthesizing a composite fluorescent sensing material

[0025] The precursor molecule R1-FR2-R3 and the metal salt compound are respectively dissolved in a third solvent, and the reaction is completed at room temperature; after the reaction is completed, centrifugation, washing, and drying are performed to obtain the composite fluorescent sensing material.

[0026] In a preferred scheme, 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.

[0027] In a preferred scheme, the first basic catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, and piperidine.

[0028] In a preferred scheme, the second basic catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, and piperidine.

[0029] In a preferred scheme, the molar ratio of the precursor molecule R1-FR2-R3 and the metal salt compound in step S2 is (1-16):1.

[0030] The present application also provides a fluorescent sensing film, which is obtained by coating the composite fluorescent sensing material on a substrate.

[0031] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0032] (1) The fluorescent sensing film prepared from the composite fluorescent sensing material provided in the present application can realize rapid detection of the vapor molecules of the methamphetamine compound and is not interfered by other organic amine compounds when detecting the methamphetamine compound. That is, the fluorescent sensing film provided in the present application has excellent selectivity for the methamphetamine compound when detecting the methamphetamine compound by the method of fluorescent sensing.

[0033] (2) The method for preparing the composite fluorescent sensing material in the present application can control the morphology and size of the composite fluorescent sensing material. The larger specific surface area of the composite fluorescent sensing material can more effectively realize enrichment of MAs molecules.

[0034] (3) Compared with directly loading a fluorescent compound on MOFs, the composite fluorescent sensing material provided in the present application has a higher loading rate of the fluorescent compound and is more sensitive to detection of MAs. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 FIG. 1 is a SEM image of the composite fluorescent sensing material prepared in Example 1 of the present application;

[0036] Figure 2 FIG. 2 is a SEM image of the composite fluorescent sensing material prepared in Example 2 of the present application;

[0037] Figure 3 SEM image of the composite fluorescent sensing material prepared in Example 3 of the present application;

[0038] Figure 4 Fluorescence spectrum of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 1 of the present application, in response to different concentrations of methamphetamine vapor;

[0039] Figure 5 Fluorescence spectrum of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 2 of the present application, in response to different concentrations of methamphetamine vapor;

[0040] Figure 6 Fluorescence spectrum of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 3 of the present application, in response to different concentrations of methamphetamine vapor;

[0041] Figure 7 Fluorescence quenching ratio bar graph of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 1 of the present application, in response to different organic amine vapors;

[0042] Figure 8 Fluorescence quenching ratio bar graph of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 2 of the present application, in response to different organic amine vapors;

[0043] Figure 9 Fluorescence quenching ratio bar graph of the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in Example 3 of the present application, in response to different organic amine vapors;

[0044] Figure 10 Fluorescence spectrum of the fluorescent sensing film prepared using the composite material of ZIF-8 loaded fluorescent compound prepared in Comparative Example 1 of the present application, in response to different concentrations of methamphetamine vapor;

[0045] Figure 11 Fluorescence spectrum of the fluorescent sensing film prepared using the composite material of ZIF-8 loaded fluorescent compound prepared in Comparative Example 2 of the present application, in response to different concentrations of methamphetamine vapor;

[0046] Figure 12 Fluorescence spectrum of the fluorescent sensing film prepared using the composite material of ZIF-8 loaded fluorescent compound prepared in Comparative Example 3 of the present application, in response to different concentrations of methamphetamine vapor. DETAILED DESCRIPTION

[0047] The technical solutions of the present application are clearly and completely described below in combination with the embodiments, so that those skilled in the art can fully understand the present application. Obviously, the described embodiments are only a part of the preferred embodiments of the present application, rather than all the embodiments. Any equivalent transformation or replacement of the following embodiments made by those skilled in the art without creative labor shall fall within the protection scope of the present application.

[0048] The specific embodiments of the present application provide a preparation method of a composite fluorescent sensing material for detecting methamphetamine, comprising the following steps:

[0049] S1, synthesis of precursor molecule R1-FR2-R3

[0050] The methyl-containing organic ligand compound R1 and the fluorinated benzene ring compound FR2 containing two aldehyde groups are respectively dissolved in a first organic solvent, a first basic catalyst is added, heated to reflux, and kept refluxing until the reaction is completed. After the reaction is completed, rotary evaporation is performed, and the obtained product is subjected to chromatography on a silica column to obtain compound A, and the chromatography eluent is a mixed solvent of dichloromethane and methanol.

[0051] Compound A and recognition molecule compound R3 are respectively dissolved in a second organic solvent, a second basic catalyst is added, heated to reflux, and kept refluxing until the reaction is completed. After the reaction is completed, rotary evaporation is performed, and the obtained product is subjected to chromatography on a silica column to obtain precursor molecule R1-FR2-R3, and the chromatography eluent is a mixed solvent of dichloromethane and methanol.

[0052] The structure of compound R3 is shown in formula I:

[0053] (Formula I), wherein R is (C n H 2n+1 ) m , n is an integer of 1-6, and m is 2 or 3.

[0054] S2, synthesis of composite fluorescent sensing material

[0055] The precursor molecule R1-FR2-R3 and the metal salt compound are respectively dissolved in a third solvent, and the reaction is completed at room temperature. After the reaction is completed, centrifugation is performed, the solid product is washed with the third solvent and then dried to obtain the composite fluorescent sensing material.

[0056] In the preferred embodiments, 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.

[0057] In a preferred embodiment, the methyl-containing organic ligand compound R1 is at least one of 2-methylimidazole, 2-methyl-1,4-benzenedicarboxylic acid, 2-methylbenzene-1,3,5-tricarboxylic acid; further preferably 2-methylimidazole.

[0058] In a preferred embodiment, the fluorinated benzene ring compound FR2 containing two aldehyde groups is any one of the structural formulae shown in formulae (1)~(17):

[0059]

[0060]

[0061]

[0062]

[0063] .

[0064] In a further preferred embodiment, the fluorinated benzene ring compound FR2 containing two aldehyde groups is the compound shown in formula (17).

[0065] In a preferred embodiment, the first organic solvent is anhydrous ethanol.

[0066] In a preferred embodiment, the first basic catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, piperidine; further preferably piperidine, 0.2 μL of piperidine is added per milliliter of the reaction system.

[0067] In a preferred embodiment, the eluent for eluting the compound A in step S1 is a mixed solvent of dichloromethane and methanol in a volume ratio of 10:1.

[0068] In a preferred embodiment, the second organic solvent is anhydrous ethanol.

[0069] In a preferred embodiment, the second basic catalyst is at least one of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, 1,3-propanediamine, 1,2-propanediamine, tripropylamine, butylamine, isobutylamine, tert-butylamine, pyridine, piperidine; further preferably piperidine, 0.2 μL of piperidine is added per milliliter of the reaction system.

[0070] In a preferred embodiment, the eluent for eluting the precursor molecule R1-FR2-R3 in step S1 is a mixed solvent of dichloromethane and methanol in a volume ratio of 10:1.

[0071] In a preferred embodiment, the metal salt compound in step S2 is a Zn-containing compound. 2+ Fe 3+ Cr 3+ Cr 6+ Co 2+ Zr 4+ Cu + Cu 2+ A metal salt compound containing at least one metal ion.

[0072] In a preferred embodiment, the molar ratio of precursor molecule R1-FR2-R3 to the metal salt compound is (1~16):1. For example, when the molar ratio of precursor molecule R1-FR2-R3 to zinc nitrate is 1:1, the resulting material has a cubic shape with a size of 600 nm. When the molar ratio of precursor molecule R1-FR2-R3 to zinc nitrate is 4:1, the resulting material has a truncated rhombic dodecahedron shape with a size of 1 μm. When the molar ratio of precursor molecule R1-FR2-R3 to zinc nitrate is 7:1, the resulting material has a truncated rhombic dodecahedron shape with a size of 600 nm. When the molar ratio of precursor molecule R1-FR2-R3 to zinc nitrate is 9:1, the resulting material has a truncated rhombic dodecahedron shape with a size of 300 nm. When the molar ratio of precursor molecule R1-FR2-R3 to zinc nitrate is 16:1, the resulting material has a truncated rhombic dodecahedron shape with a size of 100 nm.

[0073] In a preferred embodiment, the third solvent is methanol and / or water.

[0074] Example 1

[0075] A method for preparing a composite fluorescent sensing material for detecting methamphetamine-type drugs includes the following steps:

[0076] S1, Synthetic precursor molecule R1-FR2-R3

[0077] 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. The mixture was refluxed for 30 min and then refluxed at 80 °C for 4 h. After the reaction was complete, a crude solid product was obtained by rotary evaporation. The product was purified by silica column chromatography using dichloromethane / methanol (dichloromethane to methanol volume ratio of 10:1) as the eluent to obtain compound A. The main reaction equation for the synthesis of compound A is shown in Formula II.

[0078] Dissolve 351.2 mg of compound A and 728.4 mg of compound R3 in 100 mL of ethanol, add 20 μL of piperidine, reflux, activate for 30 min, and reflux at 80°C for 4 h. After the reaction is completed, obtain the crude solid product by rotary evaporation, purify by column chromatography on silica gel with dichloromethane / methanol (volume ratio of dichloromethane to methanol is 10:1) as the eluent, and obtain the precursor molecule R1-FR2-R3 containing a three-segment structure. The main reaction equation for synthesizing the precursor molecule R1-FR2-R3 is shown in formula III.

[0079]

[0080] .

[0081] S2, synthesis of composite fluorescent sensing material

[0082] Dissolve 31.268 g of the precursor molecule R1-FR2-R3 and 0.595 g of zinc nitrate hexahydrate in 20 mL of anhydrous methanol respectively, mix uniformly, and stir at room temperature for 1 h. After the reaction is completed, centrifuge, wash with methanol, collect the product, and dry to obtain the ZIF-8 composite fluorescent sensing material. The scanning electron microscope image of the composite fluorescent sensing material synthesized in this embodiment is shown in Figure 1 From the above, it can be known that the shape of the synthesized composite fluorescent sensing material is a truncated rhombic dodecahedron with a size of 300 nm. Figure 1

[0083] Example 2

[0084] A method for preparing a composite fluorescent sensing material for detecting methamphetamine, comprising the following steps:

[0085] S1, the process for synthesizing the precursor molecule R1-FR2-R3 is the same as step S1 in Example 1.

[0086] S2, synthesis of fluorescent sensing material

[0087] Dissolve 24.320 g of the precursor molecule R1-FR2-R3 and 0.595 g of zinc nitrate hexahydrate in 20 mL of methanol respectively, mix uniformly, and stir at room temperature for 1 h. After the reaction is completed, centrifuge, wash with methanol, collect the product, and dry to obtain the ZIF-8 composite fluorescent sensing material. The scanning electron microscope image of the composite fluorescent sensing material synthesized in this embodiment is shown in Figure 2 From the above, it can be known that the shape of the synthesized composite fluorescent sensing material is a truncated rhombic dodecahedron with a size of 600 nm. Figure 2

[0088] ​​The main chemical reaction equation in this embodiment is the same as that in Embodiment 1, which is not repeated here. According to the size of the composite fluorescent sensing material prepared in each of Embodiments 1 and 2, it can be seen that the size of the material can be controlled by using the method in the present application to prepare the MOFs composite fluorescent sensing material. According to the different types of organic ligand compounds R1 containing methyl groups and metal salt compounds, the prepared metal organic framework compounds (MOFs) include zeolite-imidazole framework (ZIF), Leavite organic framework (MIL), Oslo metal organic framework (UIO); combined with different reaction conditions, the size of the prepared composite fluorescent sensing material is 100-1000 nm, and the morphology is truncated rhombic dodecahedron or cube.

[0089] Embodiment 3

[0090] A preparation method of a composite fluorescent sensing material for detecting methamphetamine, comprising the following steps:

[0091] S1, the process of synthesizing the precursor molecule R1-FR2-R3 is the same as step S1 in Embodiment 1.

[0092] S2, synthesis of fluorescent sensing material

[0093] 3.474g of the precursor molecule R1-FR2-R3 and 0.595g of zinc nitrate hexahydrate were respectively dissolved in 20mL of methanol, mixed uniformly, and stirred at room temperature for 1h. After the reaction was completed, centrifugation and washing with methanol were performed, the product was collected, dried, and ZIF-8 composite fluorescent sensing material was obtained. The scanning electron microscope image of the composite fluorescent sensing material synthesized in this embodiment is shown in Figure 3 , and it can be seen from Figure 3 that the shape of the synthesized composite fluorescent sensing material is a cube with a size of 600nm.

[0094] The main chemical reaction equation in this embodiment is the same as that in Embodiment 1, which is not repeated here. According to the size of the composite fluorescent sensing material prepared in each of Embodiments 1 and 2, it can be seen that the size of the material can be controlled by using the method in the present application to prepare the MOFs composite fluorescent sensing material. According to the different types of organic ligand compounds R1 containing methyl groups and metal salt compounds, the prepared metal organic framework compounds (MOFs) include zeolite-imidazole framework (ZIF), Leavite organic framework (MIL), Oslo metal organic framework (UIO); combined with different reaction conditions, the size of the prepared composite fluorescent sensing material is 100-1000 nm, and the morphology is truncated rhombic dodecahedron or cube.

[0095] Embodiment 4

[0096] A preparation method of a fluorescent sensing film, comprising the following steps:

[0097] R1, activation of substrate: piranha solution was prepared by mixing 30 wt% hydrogen peroxide with 98 wt% concentrated sulfuric acid at a volume ratio of 3:7. A circular quartz glass slide with a diameter of 13 mm was washed with distilled water and ethanol in sequence, and then dried. The quartz glass slide was immersed in the piranha solution. The piranha solution was heated to boiling state, and activated for about 30 minutes, and then naturally cooled to room temperature. The quartz glass slide was washed with distilled water and ethanol in sequence to remove the residual piranha solution on the surface, and then dried with nitrogen.

[0098] R2, each of the composite fluorescent sensing materials prepared in Examples 1-3 was 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 dropped on the activated quartz glass slide. The spin coater was set at a rotation speed of 2000 rpm and a spin coating time of 30 seconds, and then dried in a vacuum drying oven at a pressure of 3000 Pa and a temperature of 50°C for 1 hour. The quartz glass slide was taken out, sealed, and stored, to prepare a fluorescent sensing film.

[0099] It can be understood by those skilled in the art that a quartz waveguide tube can be used instead of a quartz glass slide to prepare a fluorescent sensing film.

[0100] Example 5

[0101] In this example, the fluorescent sensing film was used to detect methamphetamine compounds, and the specific method was as follows:

[0102] Each of the fluorescent sensing films prepared in Example 4 was placed in a quartz cuvette with light transmission on four sides, and the quartz cuvette was closed with a cover. The quartz cuvette was placed in a fluorescence spectrometer, the excitation wavelength was 465 nm, the angle between the incident light and the fluorescent sensing film was 40°, and the fluorescence emission intensity was recorded as the reference value I0, i.e. the initial fluorescence emission intensity of the fluorescent sensing film without methamphetamine molecules.

[0103] To each of the quartz cuvettes, 1 μL of methamphetamine ethanol solution with a concentration of 0 ng / μL, 1 ng / μL, 10 ng / μL, and 100 ng / μL was added in sequence. When adding the sample, the solution was avoided to directly contact with the fluorescent sensing film, and then the quartz cuvette was closed with a cover. The quartz cuvette was heated to 60°C for 60 seconds to completely volatilize the sample. The quartz cuvette was placed in a fluorescence spectrometer, the excitation wavelength was 465 nm, the angle between the incident light and the fluorescent sensing film was 40°, and the fluorescence emission intensity I was measured (the fluorescence spectra are shown in FIGS. 2A-2D, respectively). The fluorescence intensity quenching rate caused by the vapor generated by volatilization of the sample can be calculated by the following formula: Figures 4-6

[0104]

[0105] In the formula, PL Q ​The fluorescence intensity quenching ratio of the fluorescence sensing film caused by the vapor generated by the sample volatilization; I0 is the reference value (fluorescence emission intensity in the quartz cuvette without adding sample), and I is the fluorescence emission intensity after the vapor generated by the sample volatilization contacts the fluorescence sensing film.

[0106] From Figure 4 It can be seen from the above that the emission wavelength of the fluorescence sensing film prepared from the composite fluorescence sensing material prepared in Example 1 is located at 606 nm, and the reference value I0 is 4627. The I value after the volatilization of the ethanol solution is 3726, and the I values after the volatilization of the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 2681, 2597 and 2447 respectively. It is calculated that the fluorescence intensity quenching ratios PL caused by the volatilization of ethanol and the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 29.2%, 42.1%, 43.9% and 47.1% respectively. Q

[0107] From Figure 5 It can be seen from the above that the emission wavelength of the fluorescence sensing film prepared from the composite fluorescence sensing material prepared in Example 2 is located at 606 nm, and the reference value I0 is 4710. The I value after the volatilization of the ethanol solution is 3357, and the I values after the volatilization of the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 2042, 908 and 689 respectively. It is calculated that the fluorescence intensity quenching ratios PL caused by the volatilization of ethanol and the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 28.7%, 56.7%, 80.7% and 85.4% respectively. Q

[0108] From Figure 6 It can be seen from the above that the emission wavelength of the fluorescence sensing film prepared from the composite fluorescence sensing material prepared in Example 3 is located at 606 nm, and the reference value I0 is 4413. The I value after the volatilization of the ethanol solution is 3692, and the I values after the volatilization of the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 3448, 2984 and 2719 respectively. It is calculated that the fluorescence intensity quenching ratios PL caused by the volatilization of ethanol and the 1 ng / μL, 10 ng / μL and 100 ng / μL methamphetamine ethanol solutions are 16.3%, 21.9%, 32.4% and 38.4% respectively. Q

[0109] Example 6

[0110] In this example, the selectivity of the fluorescence sensing film prepared in Example 4 is studied, and the specific method is as follows:

[0111] ​​​The I0 values ​​of the various fluorescent sensing films prepared in Example 4 were determined according to the method described in Example 5. The different fluorescent sensing films prepared in Example 4 were each placed in a four-sided transparent quartz cuvette, and 1 μL of each of the following solutions (100 ng / μL each): diisopropylamine ethanol solution, monoisopropylamine ethanol solution, aniline ethanol solution, and triethylamine ethanol solution. Direct contact between the solution and the fluorescent sensing film was avoided during sample addition. The quartz cuvette was then sealed. The quartz cuvette was heated to 60°C and held for 60 seconds to allow complete evaporation of the sample. The quartz cuvette was placed in a fluorescence spectrometer with an excitation wavelength of 465 nm and an incident light angle of 40° with the fluorescent sensing film. The fluorescence emission intensity I was measured, and PL was calculated according to the formula in Example 5. Q Different fluorescent sensing films detect the fluorescence intensity quenching ratio (PL) induced by various organic amine compounds. Q The bar charts are as follows: Figures 7-9 As shown.

[0112] from Figure 7 As can be seen above, when the fluorescent sensing film prepared using 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.

[0113] from Figure 8 As can be seen above, when the fluorescent sensing film prepared using 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.

[0114] from Figure 9 As can be seen above, when the fluorescent sensing film prepared using 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.

[0115] from Figures 7-9 As can be seen above, at the same sample concentration, regardless of which fluorescent sensing film from Example 4 is used, the fluorescence quenching rate caused by methamphetamine is much higher than that of other organic amine compounds. This indicates that the fluorescent sensing film prepared using the composite fluorescent sensing material prepared in this application has significant selectivity for methamphetamine compounds.

[0116] Comparative Example 1

[0117] A method for preparing a composite material of ZIF-8 loaded with a fluorescent compound includes the following steps:

[0118] S1, synthesis of fluorescent compound FR2-R3

[0119] Dissolve 0.268 g of tetrafluoroterephthaldehyde and 0.728 g of compound R3 in 100 mL of ethanol, add 20 μL of piperidine, reflux, activate for 30 min, and reflux at 80°C for 4 h. After the reaction is completed, obtain the crude solid product by rotary evaporation, purify by silica column chromatography with dichloromethane / methanol (volume ratio of dichloromethane to methanol is 10:1) as the eluent, and obtain the fluorescent compound FR2-R3. The main reaction equation for synthesizing the fluorescent compound FR2-R3 is shown in Formula IV.

[0120]

[0121] S2, synthesis of MOF-loaded fluorescent compound composite

[0122] Dissolve 1.478 g of 2-methylimidazole, 0.595 g of zinc nitrate hexahydrate, and 26.653 g of fluorescent compound FR2-R3 in 20 mL of methanol solution respectively, mix uniformly, and stir at room temperature for 1 h. After the reaction is completed, centrifuge, wash with methanol, collect the product, and dry to obtain the ZIF-8-loaded fluorescent compound composite. The size and morphology of the ZIF-8-loaded fluorescent compound composite synthesized in this comparative example are the same as those of Example 1, and the shape is a truncated rhombic dodecahedron with a size of 300 nm.

[0123] Comparative Example 2

[0124] A method for preparing a ZIF-8-loaded fluorescent compound composite, comprising the following steps:

[0125] S1, the process for synthesizing the fluorescent compound FR2-R3 is the same as step S1 in Comparative Example 1.

[0126] S2, synthesis of MOF-loaded fluorescent compound composite

[0127] Dissolve 1.478 g of 2-methylimidazole, 0.595 g of zinc nitrate hexahydrate, and 26.653 g of fluorescent compound FR2-R3 in 20 mL of methanol solution respectively, mix uniformly, and stir at room temperature for 1 h. After the reaction is completed, centrifuge, wash with methanol, collect the product, and dry to obtain the ZIF-8-loaded fluorescent compound composite. The size and morphology of the ZIF-8-loaded fluorescent compound composite synthesized in this comparative example are the same as those of Example 1, and the shape is a truncated rhombic dodecahedron with a size of 300 nm.

[0128] Comparative Example 3

[0129] A method for preparing a ZIF-8 loaded fluorescent compound composite material, comprising the following steps:

[0130] S1, the process for synthesizing fluorescent compound FR2-R3 is the same as step S1 in Comparative Example 1.

[0131] S2, synthesis of MOF loaded fluorescent compound composite material

[0132] 0.164g 2-methylimidazole, 0.595g zinc nitrate hexahydrate and 20.730g fluorescent compound FR2-R3 were respectively dissolved in 20mL methanol solution, mixed uniformly and stirred at room temperature for 1h. After the reaction was completed, centrifugation and washing with methanol were performed, the product was collected and dried to obtain a ZIF-8 loaded fluorescent compound composite material. The size and morphology of the ZIF-8 loaded fluorescent compound composite material synthesized in this comparative example are the same as those of Example 3, and the shape is a cube with a size of 600nm.

[0133] Comparative Example 4

[0134] The composite fluorescent sensing material prepared in each of Examples 1-3 was respectively replaced by the ZIF-8 loaded fluorescent compound composite material prepared in each of Comparative Examples 1-3 in step R2 of Example 4 to prepare three kinds of fluorescent sensing films.

[0135] Comparative Example 5

[0136] According to the same method in Example 5, each fluorescent sensing film prepared in Comparative Example 4 was used to detect methamphetamine compounds, and the obtained fluorescence spectrum is shown in Figures 10-12 .

[0137] From Figure 10 the above, it can be seen that the emission wavelength of the fluorescent sensing film prepared by using the ZIF-8 loaded fluorescent compound composite material prepared in Comparative Example 1 is located at 606nm, and the reference value I0 is 1962. After ethanol volatilization, the I value is 1750, and after volatilization of 1ng / μL, 10ng / μL and 100ng / μL methamphetamine ethanol solution, the I values are 1745, 1734 and 1705 respectively. After calculation, the fluorescence quenching rate PL Q of ethanol and 1ng / μL, 10ng / μL and 100ng / μL methamphetamine ethanol solution after volatilization is 10.8%, 11.1%, 11.6% and 13.1% respectively. It can be seen that when the ZIF-8 loaded fluorescent compound composite material prepared in Comparative Example 1 is used to detect methamphetamine, the fluorescence quenching rate is not greatly improved compared with anhydrous ethanol, and the detection of methamphetamine cannot be realized.

[0138] From Figure 11As can be seen above, the fluorescence sensing film prepared using the ZIF-8-loaded fluorescent compound composite material prepared in Comparative Example 2 has an emission wavelength of 606 nm and a reference value I0 of 2681. After ethanol evaporation, the I0 value is 2447, and after evaporation of 1 ng / μL, 10 ng / μL, and 100 ng / μL methamphetamine ethanol solutions, the I0 values ​​are 2424, 2433, and 2157, respectively. The calculated fluorescence intensity quenching ratio PL caused by the evaporation of ethanol and 1 ng / μL, 10 ng / μL, and 100 ng / μL methamphetamine ethanol solutions is... Q The values ​​were 8.7%, 9.3%, 9.6%, and 19.5%, respectively. It is evident that when using the ZIF-8-loaded fluorescent compound composite material prepared in Comparative Example 2 to detect methamphetamine, a sufficiently high concentration of methamphetamine (detection limit of 100 ng / μL) is required to clearly distinguish it from the fluorescence intensity quenching ratio produced by anhydrous ethanol.

[0139] from Figure 12 As can be seen above, the fluorescence sensing film prepared using the ZIF-8-loaded fluorescent compound composite material prepared in Comparative Example 3 has an emission wavelength of 606 nm and a reference value I0 of 1819. After ethanol evaporation, the I0 value is 1764. The I0 values ​​after evaporation of 1 ng / μL, 10 ng / μL, and 100 ng / μL methamphetamine ethanol solutions are 1764, 1749, and 1611, respectively. The fluorescence intensity quenching ratio PL caused by the evaporation of ethanol and 1 ng / μL, 10 ng / μL, and 100 ng / μL methamphetamine ethanol solutions is calculated to be... Q The concentrations were 3%, 3%, 3.8%, and 11.4%, respectively. It is evident that when using the ZIF-8-loaded fluorescent compound composite material prepared in Comparative Example 3 to detect methamphetamine, a sufficiently high concentration of methamphetamine (detection limit of 100 ng / μL) is required to clearly distinguish it from the fluorescence intensity quenching ratio produced by anhydrous ethanol.

[0140] In summary, the fluorescence sensing film prepared using the composite fluorescence sensing material provided in this application exhibits significantly higher sensitivity for detecting methamphetamine than the fluorescence sensing film prepared using the ZIF-8-loaded fluorescent compound composite material in the comparative example. This is primarily due to the higher fluorescent compound loading achieved using the preparation method described in this application.

[0141] The embodiments described above are merely preferred embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by anyone skilled in the art. Any simple equivalent changes and modifications made based on the scope of protection of this application and the content of the specification should be included within the scope of protection of this application.

Claims

1. A composite fluorescent sensing material for detecting methamphetamine, 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 compound R3 has the following structural formula: ； wherein R is (C n H 2n+1 ) m , n is an integer from 1 to 6, m is 2 or 3; the methyl-containing organic ligand compound R1 is 2-methylimidazole; the fluorinated benzene ring compound FR2 containing two aldehyde groups has a structure formula shown in any one of formulas (1) to (17): ； The metal salt compound is a metal salt compound containing Zn 2+ ; the preparation method of the precursor molecule R1-FR2-R3 includes the following steps: dissolving the organic ligand compound R1 containing a methyl group and the fluorinated benzene ring compound FR2 containing two aldehyde groups in a first organic solvent respectively, adding a first basic catalyst, heating to reflux, maintaining reflux until the reaction is completed; after the reaction is completed, rotary evaporation is performed, the obtained product is subjected to chromatography on a silica column using a mixed solvent of dichloromethane and methanol, and compound A is obtained; dissolving compound A and compound R3 in a second organic solvent respectively, adding a second basic catalyst, heating to reflux, maintaining reflux until the reaction is completed; after the reaction is completed, rotary evaporation is performed, the obtained product is subjected to chromatography on a silica column using a mixed solvent of dichloromethane and methanol, and the precursor molecule R1-FR2-R3 is obtained.

2. The method of claim 1, wherein the composite fluorescent sensing material is prepared by the steps of: The method comprises the following steps: The precursor molecule R1-FR2-R3 and the metal salt compound are respectively dissolved in a third solvent, and are reacted at room temperature until the reaction is complete; after the reaction is completed, centrifugation, washing, and drying are performed to obtain the composite fluorescent sensing material.

3. The method for preparing the composite fluorescent sensing material according to claim 2, 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 to the metal salt compound is (1-16):

1.

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

5. A fluorescent sensing film, characterized by, The fluorescent sensing film is obtained by coating the composite fluorescent sensing material of claim 1 on a substrate.

6. Application of the composite fluorescent sensing material of claim 1 in detecting methamphetamine.

7. Application of the fluorescent sensing film of claim 5 in detecting methamphetamine.

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