Naphthalimide-pyrene exciplex probe for fluorescence detection of MDMB-5F-PINACA synthetic cannabinoid

Abstract

The invention provides a naphthalimide-pyrene exciplex probe for fluorescence detection of MDMB-5F-PINACA synthetic cannabinoid, the probe takes naphthalimide as a recognition group and a pyrene exciplex as a luminescence center, and the probe can be obtained through nucleophilic substitution and Schiff base reaction. Before and after the MDMB-5F-PINACA is added into the naphthalimide-pyrene exciplex probe to synthesize cannabinoid, the fluorescence color is changed from blue to green; the probe presents a ratiometric fluorescence signal. In order to facilitate on-site actual detection application, the probe is loaded on a silicon wafer substrate to prepare a sensing chip, after MDMB-5F-PINACA is dropwise added to synthesize a cannabinoid solution, the fluorescence color is changed from colorless to green, and detection is not interfered by other common coexisting substances. The method has the advantages of high sensitivity, high specificity, rapidness and visualization, and has a wide application prospect in field analysis of trace chemical substances.

Description

Technical Field

[0001] The invention belongs to the field of analytical chemistry and provides a naphthalimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids. The probe has a low detection limit, strong anti-interference ability, and a short reaction time, and can achieve the purpose of low-cost and high-performance detection of MDMB-5F-PINACA synthetic cannabinoids. Background Art

[0002] Synthetic cannabinoids originate from the plant cannabis and are a class of new artificially synthesized psychoactive substances. Based on the interaction with CB1\CB2 proteins in the body, they can cause addiction, anxiety, mental illness, heart disease, epilepsy, vomiting and other symptoms. The MDMB-CA series has become a prominent subclass because the tert-butyl group on its head has been shown to have a high affinity with receptor proteins, resulting in strong toxicity and addiction. Its abuse forms are diverse and its disguise is strong, so it is of great significance to achieve its high sensitivity, rapid response and selective on-site detection.

[0003] Compared with other on-site detection methods, such as chromatography-mass spectrometry, infrared spectroscopy, Raman spectroscopy, electrical analysis, ion mobility spectrometry, etc., the visualization optical sensing method based on colorimetry and fluorescence technology can utilize the selective interaction between the designed recognition base and the target molecule to change its stacking state or chemical structure, and the intensity of the resulting changed light signal is accumulated to output a visual signal that can be detected. Because of its many excellent characteristics such as intuitive results, adjustable structure, high specificity, fast response speed, and high device modularity, it has become one of the important solutions for on-site detection of trace substances. At present, there are few reports on the fluorescence detection of synthetic cannabinoids based on small molecule probes. The reason is that its chemical structure is complex (non-planar, nonlinear), the chemical activity of the functional groups it contains is weak, and it is difficult to identify through covalent reactions. Therefore, the development of new fluorescent probes for synthetic cannabinoids is a major challenge in the field.

[0004] The present invention develops a naphthalene imide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoid. The probe uses the exciplex emission of pyrene as a fluorophore and the naphthalene imide group as a reaction site of the probe. Through multiple interactions, MDMB-5F-PINACA molecules are captured in two naphthalene imide parts of the probe. The MDMB-5F-PINACA synthetic cannabinoid and the probe are combined through metal complexation, π-π stacking and van der Waals force triple interactions, which is specifically manifested in that Zn ions are coordinated with oxygen atoms on the connecting group of MDMB-5F-PINACA, while the synthetic cannabinoid The indazole core group is π-π stacked with two naphthalimide parts, and its tail fat chain interacts with the fat chain on one of the naphthalimide of the probe through van der Waals force. Therefore, energy transfer occurs between the probe and the synthetic cannabinoid, and the energy is transferred from the pyrene exciplex part to the part where the naphthalimide and the synthetic cannabinoid are combined, resulting in a change in fluorescence from the blue fluorescence of the pyrene exciplex to green fluorescence, thereby achieving specific and accurate identification of the MDMB-CA series of synthetic cannabinoids. At the same time, highly specific and highly sensitive on-site rapid fluorescence detection of MDMB-5F-PINACA synthetic cannabinoids is achieved using detection reagents or silicon-based sensor chips. Summary of the invention

[0005] The present invention aims to provide a naphthalimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids, the probe uses naphthalimide as a recognition group, pyrene exciplex as a luminescent center, and can obtain a naphthalimide-pyrene exciplex probe by nucleophilic substitution and Schiff base reaction, the probe can realize ratio fluorescence detection of MDMB-5F-PINACA, before and after adding MDMB-5F-PINACA synthetic cannabinoids, the fluorescence color changes from blue to green, and the probe presents a ratio fluorescence signal. In order to facilitate the actual detection application on site, the naphthalimide-pyrene exciplex probe is loaded on a silicon wafer substrate to make a sensor chip, and after dropping a synthetic cannabinoid solution, the fluorescence color changes from colorless to green. In addition, the sensor chip is loaded into a portable detection pool, and a solid or liquid suspicious object can be extracted by an integrated extraction unit, and the sensor chip is dripped into the sensor chip through a funnel-shaped device after enrichment, so as to realize the detection of trace MDMB-CA series synthetic cannabinoids, and the detection is not interfered by other common structural analogs and tobacco oil additives. The invention has the advantages of high sensitivity, high specificity, rapidity and visualization, and has broad application prospects in on-site analysis.

[0006] The naphthylimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids described in the present invention has a chemical name of zinc-(2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione), and its structural formula (I) is:

[0007]

[0008] The method for preparing a naphthylimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids is carried out according to the following steps:

[0009] Preparation of detection reagents:

[0010] a. Add 4-bromo-1,8-naphthalene dicarboxylic anhydride solid and n-butylamine liquid into a round-bottom flask containing ethanol and mix, reflux and heat at 80° C. for 8 hours, then cool to room temperature and precipitate to obtain a crude product, which is recrystallized from ethanol to obtain 4-bromo-n-butyl-1,8-naphthalene imide;

[0011] b. The 4-bromo-n-butyl-1,8-naphthalimide obtained in step a and ethane-1,2-diamine liquid were added to a round-bottom flask containing 2-methoxyethanol and mixed, heated and stirred in an oil bath at 120° C. for 8 hours, cooled to room temperature, poured into water, precipitated to obtain a crude product, and the crude product was recrystallized from ethanol to obtain n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide;

[0012] c. 1-pyrene carboxaldehyde and the n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide obtained in step b were dissolved in 15 ml of absolute ethanol and mixed, stirred and refluxed at a temperature of 30° C. for 24 hours, excess ethanol was removed, and the mixture was allowed to stand overnight at room temperature until a yellow precipitate appeared, and the precipitate was washed with absolute ethanol to obtain (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione);

[0013] d. At room temperature, the (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione) obtained in step c was mixed with zinc chloride in methanol, stirred at room temperature for 8 hours, and then the methanol was removed under vacuum, and washed with a methanol / water mixed solution with a volume ratio of 1:1 to obtain a naphthylimide-pyrene exciplex probe in the form of an orange solid;

[0014] Detection of MDMB-5F-PINACA synthetic cannabinoids using naphthylimide-pyrene exciplex probe:

[0015] e. Dissolve the naphthylimide-pyrene exciplex probe obtained in step d in methanol / water at a volume ratio of 1:9, dissolve by ultrasonication, and prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 0.01-1 mmol / L to obtain a detection reagent for identifying MDMB-5F-PINACA synthetic cannabinoids;

[0016] g. Place the naphthylimide-pyrene exciplex probe solution obtained in step e in a test tube, then add the MDMB-5F-PINACA synthetic cannabinoid solution to be tested, and after sufficient reaction, record the fluorescence spectrum and optical photographs under 365nm ultraviolet light excitation conditions, and observe the signal changes of the fluorescence characteristic emission peak before and after the reaction;

[0017] Alternatively, the naphthylimide-pyrene exciplex probe is spin-coated on a silicon wafer substrate at a rotation speed of 2000 rpm, the spin-coated film is vacuumed at a temperature of 45°C for 10 minutes, and purged with nitrogen for 10 minutes to remove residual solvent and impurities, thereby obtaining a sensor chip loaded with the naphthylimide-pyrene exciplex probe; 5 μL of the MDMB-5F-PINACA synthetic cannabinoid solution to be detected is drawn and dropped onto the sensor chip loaded with the probe, and the fluorescence change is observed under 365 nm illumination conditions.

[0018] The present invention discloses a naphthalimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids. In the method, the probes with naphthalimide as response groups can realize ratio fluorescence detection of MDMB-5F-PINACA synthetic cannabinoids, wherein the detection limit of the probe for MDMB-5F-PINACA synthetic cannabinoids can reach 0.78ng, the detection linear range is 0.04-50μg, and within 10s of dripping the analyte, its fluorescence color changes from blue to green, and other common structural analogs and electronic cigarette oil additives have no obvious interference with the detection of synthetic cannabinoids. The present invention has no special restrictions when used, and qualitative detection can be quickly completed at room temperature without pre-treatment of the analyte, and the operation is simple, economical and practical, with high specificity and sensitivity, and the results are stable and repeatable. The above advantages make the present invention easy to be practically applied and promoted in the field of on-site instant detection.

[0019] In the presence of synthetic cannabinoids, the probe exhibits an obvious ratio fluorescence change, that is, blue turns green; after dropping the synthetic cannabinoid solution, an obvious fluorescence response change can occur within 10 seconds; the probe has good recognition ability for MDMB-5F-PINACA synthetic cannabinoids, and the detection is not interfered by other common structural analogs and electronic cigarette oil additives. The present invention provides a good research basis and effective means of investigation for rapid on-site analysis.

[0020] The present invention discloses a naphthylimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids. The detection principle of the method is as follows: the carbonyl group of the synthetic cannabinoid to be detected forms a coordination effect with the zinc ion of the probe molecule, the indazole parent nucleus of the synthetic cannabinoid forms a π-π stacking effect with the naphthylimide group, the alkyl chain in the probe also forms a van der Waals force with the tail of the to-be-detected object, and the multiple forces of the probe combine with the product molecule to realize the corresponding fluorescence color change. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The detection effect of the naphthylimide-pyrene-based probe on the MDMNB-5F-PINACA synthetic cannabinoid in Example 1 of the present invention; wherein a is a photograph of the detection effect of the naphthylimide-pyrene-based probe on the MDMNB-5F-PINACA synthetic cannabinoid, and b is a fluorescence spectrum of the detection effect of the naphthylimide-pyrene-based probe on the MDMNB-5F-PINACA synthetic cannabinoid;

[0022] Figure 2 The detection effect of the series of concentration probe molecules in Examples 2-5 of the present invention on MDMB-5F-PINACA synthetic cannabinoids; wherein a is a fluorescence spectrum diagram of the detection effect of the series of concentration probe molecules on MDMB-5F-PINACA synthetic cannabinoids, b is a dot-line diagram of the detection effect of the series of concentration probe molecules on MDMB-5F-PINACA synthetic cannabinoids, and c is a photograph of the detection effect of the series of concentration probe molecules on MDMB-5F-PINACA synthetic cannabinoids;

[0023] Figure 3 The fluorescence changes before and after the reaction of the naphthalimide-pyrene-based probe molecule to detect the synthetic cannabinoid of a series of concentrations MDMB-5F-PINACA, and the correlation between the fluorescence changes and the concentration of the synthetic cannabinoid in Example 6 of the present invention; wherein a is a photograph before and after the reaction of the naphthalimide-pyrene-based probe molecule to detect the synthetic cannabinoid of a series of concentrations MDMB-5F-PINACA, b is a fluorescence spectrum before and after the reaction of the naphthalimide-pyrene-based probe molecule to detect the synthetic cannabinoid of a series of concentrations MDMB-5F-PINACA, and c is a linear relationship fitting diagram before and after the reaction of the naphthalimide-pyrene-based probe molecule to detect the synthetic cannabinoid of a series of concentrations MDMB-5F-PINACA;

[0024] Figure 4 The detection effect of the naphthylimide-pyrene-based probe molecule in Example 7 of the present invention on the detection of MDMB series synthetic cannabinoids; a is a fluorescence spectrum diagram of the detection effect of the naphthylimide-pyrene-based probe molecule on the detection of MDMB series synthetic cannabinoids, and b is a bar graph and a photograph of the detection effect of the naphthylimide-pyrene-based probe molecule on the detection of MDMB series synthetic cannabinoids;

[0025] Figure 5 The detection effect of the naphthylimide-pyrene-based probe molecule in Example 8 of the present invention on detecting MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs and electronic cigarette oil additives; wherein a is a photograph of the detection effect of the naphthylimide-pyrene-based probe molecule on detecting MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs and electronic cigarette oil additives, and b is a fluorescence spectrum of the detection effect of the naphthylimide-pyrene-based probe molecule on detecting MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs and electronic cigarette oil additives;

[0026] Figure 6 This is the detection effect of the silicon wafer substrate loaded probe detecting the MDMB-5F-PINACA synthetic cannabinoid methanol droplet in Example 9 of the present invention; a is the fluorescence microscope and scanning electron microscope image of the silicon wafer substrate loaded probe detecting the MDMB-5F-PINACA synthetic cannabinoid methanol droplet before the reaction, and b is the fluorescence microscope and scanning electron microscope image of the silicon wafer substrate loaded probe detecting the MDMB-5F-PINACA synthetic cannabinoid methanol droplet after the reaction for h;

[0027] Figure 7 1 is the detection effect of the silicon wafer substrate loaded probe detecting a series of concentrations of MDMB-5F-PINACA synthetic cannabinoid methanol droplets in Example 10 of the present invention; wherein a is a photograph of the detection effect of the silicon wafer substrate loaded probe detecting a series of concentrations of MDMB-5F-PINACA synthetic cannabinoid methanol droplets, and b is a linear relationship fitting diagram of the detection effect of the silicon wafer substrate loaded probe detecting a series of concentrations of MDMB-5F-PINACA synthetic cannabinoid methanol droplets;

[0028] Figure 8 1 is the detection effect of the naphthylimide-pyrene-based probe-silicon wafer substrate sensor chip in Example 11 of the present invention on MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs; wherein a is a photograph of the detection effect of the naphthylimide-pyrene-based probe-silicon wafer substrate sensor chip on MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs, and b is a spherical distribution diagram of the detection effect of the naphthylimide-pyrene-based probe-silicon wafer substrate sensor chip on MDMB-5F-PINACA synthetic cannabinoid and other common structural analogs;

[0029] Fig. 9This is the detection effect of the portable detection cabin sensor device in Example 12 of the present invention on the MDMB-5F-PINACA synthetic cannabinoid mixed in the real sample; wherein a is a schematic diagram of the application scenario of the portable detection cabin, b is a schematic diagram of the structure of the portable detection cabin, and c is a photograph of the detection effect of the portable detection cabin sensor device on the MDMB-5F-PINACA synthetic cannabinoid mixed in the real sample. DETAILED DESCRIPTION

[0030] The present invention is further described below by means of specific examples, but the invention is not limited to these examples.

[0031] Example 1

[0032] Preparation of naphthylimide-pyrene-based probe:

[0033] a. 1.662 g, 6 mmol, of 4-bromo-1,8-naphthalene dicarboxylic anhydride solid and 1.78 ml, 18 mmol, of n-butylamine liquid were added to a round-bottom flask containing 36 ml of ethanol and mixed. The mixture was refluxed and heated at 80° C. for 8 hours, then cooled to room temperature, and precipitated to obtain a crude product. The crude product was recrystallized from ethanol to obtain 4-bromo-n-butyl-1,8-naphthalene imide;

[0034] b. 0.2 g, 0.6 mmol of 4-bromo-n-butyl-1,8-naphthalimide obtained in step a and 100 μl of ethane-1,2-diamine liquid, 1.5 mmol were added to a round-bottom flask containing 40 ml of 2-methoxyethanol and mixed. The mixture was heated and stirred in an oil bath at 120° C. for 8 hours, cooled to room temperature, and then poured into 100 ml of water to precipitate to obtain a crude product. The crude product was recrystallized in ethanol to obtain n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide;

[0035] c. 0.075 g, 0.33 mmol of 1-pyrenecarboxaldehyde and 0.1 g, 0.32 mmol of n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide obtained in step b were dissolved in 15 ml of anhydrous ethanol and mixed, and the mixture was then stirred and refluxed at a temperature of 30° C. for 24 hours, excess ethanol was removed, and the mixture was allowed to stand overnight at room temperature until a yellow precipitate appeared, and the precipitate was washed with anhydrous ethanol to obtain (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione);

[0036] d. At room temperature, 1.1 g, 2.1 mmol of (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione) obtained in step c was mixed with 0.14 g, 1.0 mmol of zinc chloride in 50 ml of methanol. After stirring at room temperature for 8 hours, the methanol was removed under vacuum and washed with a mixture of methanol / water in a volume ratio of 1:1 to obtain a naphthylimide-pyrene exciplex probe in the form of an orange solid;

[0037] Preparation of detection reagents:

[0038] e. Dissolve the naphthylimide-pyrene exciplex probe obtained in step d in methanol / water at a volume ratio of 1:9, dissolve by ultrasonication, and prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 0.01 mmol / L to obtain a detection reagent for identifying MDMB-5F-PINACA synthetic cannabinoids;

[0039] Detection of MDMB-5F-PINACA synthetic cannabinoids:

[0040] g. Take 180 μL of the 0.05 mmol / L naphthylimide-pyrene exciplex probe solution obtained in step e into a test tube, then add 0.1 mmol / L MDMB-5F-PINACA synthetic cannabinoid methanol solution. After sufficient reaction, select an excitation wavelength of 365 nm, record the fluorescence spectrum and take a fluorescence picture; the detection effect of the naphthylimide-pyrene exciplex probe molecule on synthetic cannabinoids in a methanol / water solution with a volume ratio of 1:9 is as follows: Figure 1 As shown, under the irradiation of 365nm ultraviolet light, the fluorescence color of the reagent changes from blue to green. In addition, when measured by fluorescence spectrometer, the excitation wavelength is selected as 365nm, and the fluorescence characteristic peak blue-shifts from 470nm to 515nm. The above phenomenon shows obvious fluorescence changes.

[0041] Example 2

[0042] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0043] Preparation of detection reagents:

[0044] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 10 μmol / L, and then 180 μL of the naphthylimide-pyrene exciplex probe solution of the corresponding concentration was taken into a test tube to obtain a detection reagent;

[0045] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0046] Using methanol as solvent, prepare a synthetic cannabinoid standard solution with a concentration of 0.1 mmol / L;

[0047] Testing process:

[0048] Pipette 20 μL of MDMB-5F-PINACA synthetic cannabinoid standard solution and add it to 10 μmol / L detection reagent. After sufficient reaction, select the excitation wavelength as 365 nm, record the fluorescence spectrum and take a fluorescence picture.

[0049] Detection effect:

[0050] The detection effect of 10 μmol / L naphthylimide-pyrene exciplex probe solution on MDMB-5F-PINACA synthetic cannabinoids is as follows Figure 2 As shown, under 365nm ultraviolet light, the fluorescence color of the reagents turned green after reaction, and the response time was less than 3s;

[0051] Subsequently, the spectra before and after detection were measured using a fluorescence spectrometer. Under 365nm excitation, a new emission peak appeared at 517nm in the fluorescence spectrum, while the peak intensity at 480nm weakened, confirming the presence of MDMB-5F-PINACA synthetic cannabinoid.

[0052] Example 3

[0053] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0054] Preparation of detection reagents:

[0055] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 20 μmol / L, and then 180 μL of the naphthylimide-pyrene exciplex probe solution of corresponding concentration was taken into a test tube to obtain a detection reagent;

[0056] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0057] Using methanol as solvent, prepare a synthetic cannabinoid standard solution with a concentration of 0.1 mmol / L;

[0058] Testing process:

[0059] Pipette 20 μL of MDMB-5F-PINACA synthetic cannabinoid standard solution and add it to 20 μmol / L detection reagent. After sufficient reaction, select the excitation wavelength as 365 nm, record the fluorescence spectrum and take a fluorescence picture.

[0060] Detection effect:

[0061] The detection effect of 20 μmol / L naphthylimide-pyrene exciplex probe solution on MDMB-5F-PINACA synthetic cannabinoids is as follows Figure 2 As shown, under 365nm ultraviolet light, the fluorescence color of the reagents turned green after reaction, and the response time was less than 3s;

[0062] Subsequently, the spectra before and after detection were measured using a fluorescence spectrometer. Under 365nm excitation, a new emission peak appeared at 517nm in the fluorescence spectrum, while the peak intensity at 480nm weakened, confirming the presence of MDMB-5F-PINACA synthetic cannabinoid.

[0063] Example 4

[0064] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0065] Preparation of detection reagents:

[0066] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 50 μmol / L, and then 180 μL of the naphthylimide-pyrene exciplex probe solution of corresponding concentration was taken into a test tube to obtain a detection reagent;

[0067] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0068] Using methanol as solvent, prepare a synthetic cannabinoid standard solution with a concentration of 0.1 mmol / L;

[0069] Testing process:

[0070] Pipette 20 μL of MDMB-5F-PINACA synthetic cannabinoid standard solution and add it to 50 μmol / L detection reagent. After sufficient reaction, select the excitation wavelength as 365 nm, record the fluorescence spectrum and take a fluorescence picture.

[0071] Detection effect:

[0072] The detection effect of 50 μmol / L naphthylimide-pyrene exciplex probe solution on MDMB-5F-PINACA synthetic cannabinoids is as follows Figure 2 As shown, under 365nm ultraviolet light, the fluorescence color of the reagents turned green after reaction, and the response time was less than 3s;

[0073] Subsequently, the spectra before and after detection were measured using a fluorescence spectrometer. Under 365nm excitation, a new emission peak appeared at 517nm in the fluorescence spectrum, while the peak intensity at 480nm weakened, confirming the presence of MDMB-5F-PINACA synthetic cannabinoid.

[0074] Example 5

[0075] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0076] Preparation of detection reagents:

[0077] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 80 μmol / L, and then 180 μL of the naphthylimide-pyrene exciplex probe solution of the corresponding concentration was taken into a test tube to obtain a detection reagent;

[0078] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0079] Using methanol as solvent, prepare a synthetic cannabinoid standard solution with a concentration of 0.1 mmol / L;

[0080] Testing process:

[0081] Pipette 20 μL of MDMB-5F-PINACA synthetic cannabinoid standard solution and add it to 80 μmol / L detection reagent. After sufficient reaction, select the excitation wavelength as 365 nm, record the fluorescence spectrum and take a fluorescence picture.

[0082] Detection effect:

[0083] The detection effect of 80 μmol / L naphthylimide-pyrene exciplex probe solution on MDMB-5F-PINACA synthetic cannabinoids is as follows Figure 2 As shown. Under 365nm ultraviolet light, the fluorescence color of the reagents turned green after reaction, and the response time was less than 3s;

[0084] Subsequently, the spectra before and after detection were measured using a fluorescence spectrometer. Under 365nm excitation, a new emission peak appeared at 517nm in the fluorescence spectrum, while the peak intensity at 480nm weakened, confirming the presence of MDMB-5F-PINACA synthetic cannabinoid.

[0085] Example 6

[0086] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0087] Preparation of detection reagents:

[0088] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 100 μmol / L, and then 180 μL of the naphthylimide-pyrene exciplex probe solution of the corresponding concentration was taken into a test tube to obtain a detection reagent;

[0089] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0090] Using methanol as solvent, prepare a synthetic cannabinoid standard solution with a concentration of 0.1 mmol / L;

[0091] Testing process:

[0092] Pipette 20 μL of MDMB-5F-PINACA synthetic cannabinoid standard solution and add it to 100 μmol / L detection reagent. After sufficient reaction, select the excitation wavelength as 365 nm, record the fluorescence spectrum and take a fluorescence picture.

[0093] Detection effect:

[0094] The detection effect of 100 μmol / L naphthylimide-pyrene exciplex probe solution on MDMB-5F-PINACA synthetic cannabinoids is as follows Figure 2 As shown, under 365nm ultraviolet light, the fluorescence color of the reagents turned green after reaction, and the response time was less than 3s;

[0095] Subsequently, the spectra before and after detection were measured using a fluorescence spectrometer. Under 365nm excitation, a new emission peak appeared at 517nm in the fluorescence spectrum, while the peak intensity at 480nm weakened, confirming the presence of MDMB-5F-PINACA synthetic cannabinoid.

[0096] Example 7

[0097] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0098] Detection of MDMB-5F-PINACA synthetic cannabinoids at a series of concentrations using naphthylimide-pyrene exciplex probe:

[0099] Preparation of detection reagents:

[0100] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 100 μmol / L, and 180 μL was taken into a test tube to obtain a detection reagent;

[0101] Preparation of MDMB-5F-PINACA synthetic cannabinoid standard solution:

[0102] Using methanol as solvent, MDMB-5F-PINACA synthetic cannabinoid standard solutions with concentrations of 0.4, 0.8, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, and 2.5 mmol / L were prepared;

[0103] Testing process:

[0104] Take 20 μL of the prepared MDMB-5F-PINACA standard solution and add it to the detection reagent. After sufficient reaction, select the excitation wavelength of 365 nm and take a fluorescence photo ( Figure 3 a), and the fluorescence spectrum was measured, and the ratio of the fluorescence intensity at the characteristic peak of the product at 515 nm and the characteristic peak of the probe at 470 nm was used to make a calibration curve corresponding to the MDMB-5F-PINACA content ( Figure 3 b);

[0105] Detection effect:

[0106] like Figure 3 As shown, the change in the intensity ratio of the characteristic peak of the product to the characteristic peak of the probe after the naphthylimide-pyrene exciplex probe molecule detected MDMB-5F-PINACA synthetic cannabinoid in a methanol / water solution system with a volume ratio of 1:9 showed a good linear relationship with the concentration change of MDMB-5F-PINACA synthetic cannabinoid in the range of 20-500 μmol / L ( Figure 3 c), therefore, the probe molecule can quantitatively detect MDMB-5F-PINACA synthetic cannabinoid molecules.

[0107] Example 8

[0108] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0109] Naphthalimide-pyrene exciplex probe for the detection of MDMB series of synthetic cannabinoids:

[0110] Detection reagent configuration:

[0111] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 0.1 mmol / L, and 180 μL of the 0.1 mmol / L naphthylimide-pyrene exciplex probe solution was taken into a test tube to obtain a detection reagent;

[0112] Preparation of test solution:

[0113] Using methanol as solvent, prepare four MDMB series synthetic cannabinoids and one other series cannabinoid, such as MDMB-5F-PINACA, MDMB-4EN-PINACA, MDMB-5F-PICA, MDMB-4F-PICA and ADB-5F-PINACA, and prepare the corresponding standard solutions with a concentration of 0.1 mmol / L;

[0114] Testing process:

[0115] Add 20 μL of 0.1 mmol / L MDMB-5F-PINACA, MDMB-4EN-PINACA, MDMB-5F-PICA, MDMB-4F-PICA and ADB-5F-PINACA synthetic cannabinoids to the prepared detection reagents, respectively. After sufficient reaction, select an excitation wavelength of 365 nm, and record fluorescence spectra and optical photographs;

[0116] Detection effect:

[0117] The detection effect of naphthylimide-pyrene exciplex probe on MDMB series synthetic cannabinoids and other types is as follows Figure 4 As shown in a, the addition of MDMB-5F-PINACA, MDMB-4EN-PINACA, MDMB-5F-PICA, and MDMB-4F-PICA synthetic cannabinoids caused the color of the detection reagent to change from blue to green, and the characteristic fluorescence peak shifted from 470nm to about 515nm. After the addition of other types of synthetic cannabinoids ADB-5F-PINACA, the blue fluorescence remained unchanged ( Figure 4 b), indicating that the naphthylimide-pyrene exciplex probe molecule has good selectivity for the MDMB series of synthetic cannabinoids.

[0118] Example 9

[0119] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0120] Selective testing of the naphthalimide-pyrene exciplex probe for the detection of MDMB-5F-PINACA synthetic cannabinoids:

[0121] Preparation of detection reagent: dissolve the naphthylimide-pyrene exciplex probe prepared in step d of Example 1 in a methanol / water solution with a volume ratio of 1:9 to prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 0.1 mmol / L, take 180 μL of the 0.1 mmol / L naphthylimide-pyrene exciplex probe solution in a test tube to obtain a detection reagent;

[0122] Preparation of test solution:

[0123] Using methanol as a solvent, other common structural analogs, common interfering substances and e-cigarette oil additives such as (S)-2-amino-3,3-dimethylbutyric acid methyl ester hydrochloride (S-MDMB), (L)-2-amino-3,3-dimethylbutyric acid methyl ester hydrochloride (L-MDMB), indole, indazole, naphthalene, ADB-5F-PINACA, morphine, fentanyl, cocaine, ketamine, methyl MDMB-5F-PINACA synthetic cannabinoids, vanillin, 1,2-propylene glycol and glycerol as interfering substances for the detection of MDMB-5F-PINACA synthetic cannabinoids, and preparing a solution with a corresponding concentration of 0.1 mmol / L;

[0124] Testing process:

[0125] Add 20 μL of 0.1 mmol / L common structural analogs, common interfering substances and e-cigarette oil additives or 0.1 mmol / L MDMB-5F-PINACA synthetic cannabinoids to the prepared detection reagent. After sufficient reaction, select the excitation wavelength of 365 nm and record the fluorescence spectrum and optical photos ( Figure 5 a);

[0126] Detection effect:

[0127] The detection effect of naphthalene imide-pyrene exciplex probe on MDMB-5F-PINACA synthetic cannabinoids and their interferents is as follows Figure 5 As shown, the addition of MDMB-5F-PINACA synthetic cannabinoid causes the color of the detection reagent to change from blue to green, and the characteristic fluorescence peak shifts from 470nm to about 515nm. The blue fluorescence remains unchanged after the addition of other interfering substances ( Figure 5 b), indicating that the naphthylimide-pyrene exciplex probe molecule has good selectivity for MDMB-5F-PINACA synthetic cannabinoid.

[0128] Example 10

[0129] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0130] The detection effect of MDMB-5F-PINACA synthetic cannabinoid methanol droplets by using the silicon wafer substrate loaded with naphthylimide-pyrene exciplex probe molecule:

[0131] Preparation of silicon wafer substrate for naphthylimide-pyrene exciplex probe:

[0132] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a chloroform solution, the probe concentration was controlled to be 0.1 mmol / L, and the solution was spin-coated on a silicon wafer substrate at a rotation speed of 2000 rpm. The spin-coated film was vacuumed at a temperature of 45° C. for 10 minutes, and purged with nitrogen for 10 minutes to remove residual solvent and impurities, thereby obtaining a sensor chip loaded with the naphthylimide-pyrene exciplex probe; 5 μL of the MDMB-5F-PINACA synthetic cannabinoid solution to be detected was added dropwise to the sensor chip loaded with the probe, and the fluorescence change was observed under 365 nm illumination to obtain a sensor chip loaded with a solid-state naphthylimide-pyrene exciplex probe;

[0133] MDMB-5F-PINACA synthetic cannabinoid standard solution configuration:

[0134] Using methanol as solvent, prepare a 0.1 mmol / L MDMB-5F-PINACA synthetic cannabinoid standard solution;

[0135] Testing process:

[0136] Take 5 μL of the prepared MDMB-5F-PINACA synthetic cannabinoid standard solution and drop it onto the obtained silicon wafer sensor chip. After sufficient contact and reaction, irradiate with white light and 365 nm ultraviolet light respectively, observe the fluorescence effect and take photos and scanning electron microscope (SEM) images;

[0137] Detection effect:

[0138] The detection effect of the silicon wafer loaded with naphthylimide-pyrene exciplex probe molecule on the MDMB-5F-PINACA synthetic cannabinoid solution is as follows Figure 6 As shown in the figure, the fluorescence color changes from colorless to green, and the fluorescence changes significantly. Under the scanning electron microscope (SEM), spherical aggregates appear on the original flat sensor chip membrane ( Figure 6 ab).

[0139] Embodiment 11

[0140] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0141] The detection effect of the silicon wafer substrate loaded with naphthylimide-pyrene exciplex probe molecule on the detection of a series of concentrations of MDMB-5F-PINACA synthetic cannabinoid methanol droplets:

[0142] Preparation of silicon wafer substrate for naphthylimide-pyrene exciplex probe:

[0143] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a chloroform solution, the probe concentration was controlled to be 0.1 mmol / L, and the solution was spin-coated on a silicon wafer substrate at a rotation speed of 2000 rpm. The spin-coated film was vacuumed at a temperature of 45° C. for 10 minutes, and purged with nitrogen for 10 minutes to remove residual solvent and impurities, thereby obtaining a sensor chip loaded with the naphthylimide-pyrene exciplex probe; 5 μL of the MDMB-5F-PINACA synthetic cannabinoid solution to be detected was added dropwise to the sensor chip loaded with the probe, and the fluorescence change was observed under 365 nm illumination to obtain a sensor chip loaded with a solid-state naphthylimide-pyrene exciplex probe;

[0144] Preparation of MDMB-5F-PINACA synthetic cannabinoid standard solution: using methanol as solvent, prepare MDMB-5F-PINACA synthetic cannabinoid standard solution with concentrations of 0.4, 0.8, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, and 2.5 mmol / L;

[0145] Testing process:

[0146] Take 5 μL of the prepared MDMB-5F-PINACA synthetic cannabinoid standard solution and drop it onto the obtained silicon chip sensor. After sufficient contact reaction, irradiate with white light and 365 nm ultraviolet light respectively, observe the colorimetric fluorescence effect and take photos ( Figure 7 ab);

[0147] Detection effect:

[0148] The detection effect of the silicon wafer loaded with naphthylimide-pyrene exciplex probe molecule on the MDMB-5F-PINACA synthetic cannabinoid solution is as follows Figure 7 As shown, the fluorescence color changes from colorless to green, and the fluorescence change is obvious.

[0149] Example 12

[0150] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0151] Silicon wafer substrate loaded with naphthylimide-pyrene exciplex probe molecule to detect MDMB-5F-PINACA synthetic cannabinoids and other common interfering substances:

[0152] Preparation of silicon wafer substrate for naphthylimide-pyrene exciplex probe:

[0153] The naphthylimide-pyrene exciplex probe prepared in step d of Example 1 was dissolved in a chloroform solution, the probe concentration was controlled to be 0.1 mmol / L, and the solution was spin-coated on a silicon wafer substrate at a rotation speed of 2000 rpm. The spin-coated film was vacuumed for 10 min at a temperature of 45° C., and purged with nitrogen for 10 min to remove residual solvent and impurities, thereby obtaining a sensor chip loaded with the naphthylimide-pyrene exciplex probe; 5 μL of the MDMB-5F-PINACA synthetic cannabinoid solution to be detected was added dropwise to the sensor chip loaded with the probe, and the fluorescence change was observed under 365 nm illumination to obtain a sensor chip loaded with a solid-state naphthylimide-pyrene exciplex probe;

[0154] Preparation of test solution:

[0155] Using methanol as a solvent and other common interfering substances such as fentanyl, cocaine, ketamine, and methamphetamine as interfering substances for the detection of MDMB-5F-PINACA synthetic cannabinoids, a methanol solution with a concentration of 0.1 mmol / L of the above interfering substances and a methanol solution of MDMB-5F-PINACA synthetic cannabinoids were prepared;

[0156] Testing process:

[0157] 5 μL of 0.1 mmol / L other common interfering substances and MDMB-5F-PINACA synthetic cannabinoids were dripped onto the configured silicon chip sensor. After sufficient reaction, the fluorescence changes were observed by irradiation with 365 nm ultraviolet light and fluorescence images were taken.

[0158] Detection effect:

[0159] Specific recognition of MDMB-5F-PINACA synthetic cannabinoid by using naphthylimide-pyrene exciplex probe molecules loaded on silicon wafer substrate Figure 8 As shown in FIG. 1 , when 5 μL of a 1 mg / mL methanol solution of MDMB-5F-PINACA synthetic cannabinoid was added to the silicon wafer substrate, the fluorescence color of the analysis card changed from colorless to green within 10 seconds ( Figure 8 a), the fluorescence changes are different from those of other interfering substances, the color RGB value is extracted, and the G / R value can be used to distinguish MDMB-5F-PINACA synthetic cannabinoids from other interfering substances ( Figure 8 b), indicating that the naphthylimide-pyrene exciplex probe molecule has good selectivity for MDMB-5F-PINACA synthetic cannabinoid and has the potential for field application.

[0160] Embodiment 13

[0161] The preparation of the naphthylimide-pyrene-based probe was carried out according to Example 1;

[0162] The prepared portable detection sensor device detects the MDMB-5F-PINACA synthetic cannabinoid mixed in the real sample:

[0163] Take any one of the naphthylimide-pyrene exciplex probes in Examples 9-11 to prepare a silicon wafer substrate to obtain a functionalized sensing material; place it in the control unit chip in the portable detection cabin obtained by 3D printing to obtain an extraction and enrichment integrated detection cabin type portable sensor device ( Fig. 9 a); When in use, add suspicious liquid or solid (such as e-cigarette oil or tobacco leaves) into the sample chamber, press the top solvent chamber, the solvent will flow out to extract the substance in the test object and enrich it in the funnel, and control the liquid to drip through the control switch, so that it contacts the sensor chip. Then, under the irradiation of an external 365nm ultraviolet lamp, observe the fluorescence change of the sensor area to qualitatively confirm whether the suspicious liquid contains MDMB-5F-PINACA ( Fig. 9 bc), when substances containing MDMB-5F-PINACA (such as e-cigarette oil, urine and tobacco leaves) are added from the sample chamber and detected and analyzed using the device, green fluorescence light-up signals can be observed under 365nm ultraviolet light ( Fig. 9 d), the results showed that the prepared extraction-enrichment integrated detection chamber device had good ability to qualitatively detect MDMB-5F-PINACA.

Claims

1. A naphthalimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoid, characterized in that The chemical name of the probe is zinc-(2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione), and its structural formula (I) is:

2. The method for preparing a naphthalimide-pyrene exciplex probe for fluorescent detection of MDMB-5F-PINACA synthetic cannabinoids as claimed in claim 1, characterized in that: Follow these steps: Prepare detection reagents: a. Add 4-bromo-1,8-naphthalene dicarboxylic anhydride solid and n-butylamine liquid into a round-bottom flask containing ethanol and mix, reflux and heat at 80° C. for 8 hours, then cool to room temperature and precipitate to obtain a crude product, which is recrystallized from ethanol to obtain 4-bromo-n-butyl-1,8-naphthalene imide; b. The 4-bromo-n-butyl-1,8-naphthalimide obtained in step a and ethane-1,2-diamine liquid were added to a round-bottom flask containing 2-methoxyethanol and mixed, heated and stirred in an oil bath at 120° C. for 8 hours, cooled to room temperature, poured into water, precipitated to obtain a crude product, and the crude product was recrystallized from ethanol to obtain n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide; c. 1-pyrene carboxaldehyde and the n-butyl-4-(2-aminoethyl)amino-1,8-naphthalimide obtained in step b were dissolved in 15 ml of absolute ethanol and mixed, stirred and refluxed at a temperature of 30° C. for 24 hours, excess ethanol was removed, and the mixture was allowed to stand overnight at room temperature until a yellow precipitate appeared, and the precipitate was washed with absolute ethanol to obtain (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione); d. At room temperature, the (2-butyl-6-((2-(((pyrene-1-yl)methylene)amino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione) obtained in step c was mixed with zinc chloride in methanol, stirred at room temperature for 8 hours, and then the methanol was removed under vacuum, and washed with a methanol / water mixed solution with a volume ratio of 1:1 to obtain a naphthylimide-pyrene exciplex probe in the form of an orange solid; Detection of MDMB-5F-PINACA synthetic cannabinoids using naphthylimide-pyrene exciplex probe: e. Dissolve the naphthylimide-pyrene exciplex probe obtained in step d in methanol / water at a volume ratio of 1:9, dissolve by ultrasonication, and prepare a naphthylimide-pyrene exciplex probe solution with a concentration of 0.01-1 mmol / L to obtain a detection reagent for identifying MDMB-5F-PINACA synthetic cannabinoids; g. Place the naphthylimide-pyrene exciplex probe solution obtained in step e in a test tube, then add the MDMB-5F-PINACA synthetic cannabinoid solution to be tested, and after sufficient reaction, record the fluorescence spectrum and optical photographs under 365nm ultraviolet light excitation conditions, and observe the signal changes of the fluorescence characteristic emission peak before and after the reaction; Alternatively, the naphthylimide-pyrene exciplex probe is spin-coated on a silicon wafer substrate at a rotation speed of 2000 rpm, the spin-coated film is vacuumed at a temperature of 45°C for 10 minutes, and purged with nitrogen for 10 minutes to remove residual solvent and impurities, thereby obtaining a sensor chip loaded with the naphthylimide-pyrene exciplex probe; 5 μL of the MDMB-5F-PINACA synthetic cannabinoid solution to be detected is drawn and dropped onto the sensor chip loaded with the probe, and the fluorescence change is observed under 365 nm illumination conditions.

Images