Application of a colorimetric and fluorescent dual-mode probe in the detection of diethyl chlorophosphate, a nerve agent mimic

Abstract

The present application relates to a kind of colorimetric fluorescence double-mode probe in the application of nerve toxic agent analog diethyl chlorophosphate, the chemical name of probe molecule is (2Z,2'Z)-3,3'-([1,1':4',1''-terphenyl]-2',5'-substituted) bis (2-(pyridine-4-yl) acrylonitrile), probe molecule is prepared into solution or sensing chip for detecting nerve toxic agent analog diethyl chlorophosphate, purified probe molecule has aggregation-induced emission (AIE) characteristics, solid-state high quantum yield (41.45%), and has intramolecular charge transfer property, simultaneously due to the polarity of probe molecule and nerve toxic agent analog is enhanced after reaction, product solubility is increased to cause fluorescence intensity to reduce;Its joint action, the fluorescence signal change of strong blue fluorescence to weak green fluorescence, the colorimetric signal change of colorless to yellow and the morphology change of aggregation to partial aggregation, realize the rapid, sensitive and specific detection of DCP.

Description

Technical Field

[0001] This invention relates to the application of a colorimetric fluorescent dual-mode probe in the nerve agent mimic diethyl chlorophosphate, belonging to the field of analytical detection. It achieves the visual detection and application of the nerve agent mimic diethyl chlorophosphate through changes in absorption and fluorescence spectra, as well as colorimetric and fluorescence color changes. Background Technology

[0002] Nerve agents are toxic chemical substances that disrupt the normal conduction function of the nervous system. They enter the human body through various routes, including the respiratory tract and skin, inhibiting cholinesterase activity and disrupting the transmission of nerve impulses. They can cause death within minutes, seriously endangering public and national security. The most representative nerve agents are tabun, sarin, soman, and VEX, which can be loaded into various munitions and missiles and are listed as chemical weapons in the first list of the Chemical Weapons Convention 2005. Therefore, highly sensitive detection of nerve agents is crucial for protecting public health and national security. Because sarin-type nerve agents are extremely toxic and pose a significant threat, simulants such as DCP, which have similar chemical structures to nerve agents but lower toxicity, are typically used to test material properties.

[0003] Currently, various detection methods for nerve agents have been developed, including mass spectrometry, ion mobility chromatography, and bio-enzyme sensors. However, due to their time-consuming, cumbersome, low-sensitivity, and poor equipment portability, they are not suitable for on-site detection. Colorimetric fluorescence dual-mode sensing technology combines the high sensitivity of fluorescence technology with the naked-eye visualization advantages of chemical colorimetry, and is also portable, making it one of the most promising methods in the field of nerve agent detection. Therefore, developing colorimetric fluorescence dual-mode probe molecules with fast response, high sensitivity, and good selectivity is a preferred approach.

[0004] Currently, some studies have been conducted on the specific detection of DCP, a nerve agent mimicking sarin, using probe molecules. However, due to its reliance on a single fluorescent signal response, the visualization effect is poor, and the probes typically use traditional fluorophores as chromophores, which suffer from high-concentration self-quenching, hindering the improvement of detection sensitivity and the long-term preservation of the sensor chip (Anal. Chem. 2016, 88, 9259-9263, ACS Sens. 2017, 2, 834-841, ACS Sens. 2020, 5, 1268-1272, Patent Application Nos.: 202010628335.3, 202211391680.5). In addition, some studies have been conducted on portable devices for DCP, which have solved the problem of high-concentration self-quenching of probes, but their long response time makes them unsuitable for on-site detection (ACS Materials Lett. 2021, 3, 249-254). Therefore, it is necessary to develop a probe molecule with the aforementioned advantages to meet the demand for efficient detection of DCP and to address the shortcomings in the on-site and rapid detection of sarin-like nerve agents. Thus, the preparation of high-performance probe molecules has become an urgent priority for the detection of sarin-like nerve agents. Summary of the Invention

[0005] The purpose of this invention is to provide a colorimetric fluorescent dual-mode probe for the application of the nerve agent mimic diethyl chlorophosphate (DCP). The chemical name of the probe molecule is (2Z,2'Z)-3,3'-([1,1':4',1”-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile). The probe molecule is prepared into a solution or sensor chip for the detection of DCP. The colorimetric fluorescent dual-mode probe molecule is used to detect DCP. The purified probe molecule exhibits aggregation-induced emission (AIE) properties and is a high-performance solid-state probe. With a quantum yield of 41.45% and intramolecular charge transfer properties, the probe uses pyridine as a recognition site. After undergoing a nucleophilic addition reaction with DCP, it hydrolyzes to change the degree of intramolecular charge transfer in the probe molecule, resulting in changes in colorimetric and fluorescence spectra. At the same time, the increased polarity of the probe molecule after reacting with DCP promotes increased product solubility, leading to a decrease in fluorescence intensity. The combined effect results in changes in fluorescence signal from strong blue fluorescence to weak green fluorescence, colorimetric signal from colorless to yellow, and morphological changes from aggregation to partial aggregation, enabling rapid, sensitive, and specific detection of DCP.

[0006] The present invention relates to the application of a colorimetric fluorescent dual-mode probe in the detection of the nerve agent mimic diethyl chlorophosphate. The chemical name of the probe molecule is (2Z,2'Z)-3,3'-([1,1':4',1”-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile). The probe molecule is prepared into a solution or a sensor chip for the detection of the nerve agent mimic diethyl chlorophosphate. The specific operation is carried out according to the following steps:

[0007] Preparation of colorimetric fluorescent dual-mode probe molecules:

[0008] a. Disperse the colorimetric fluorescent dual-mode probe in a methanol solution to obtain a colorimetric fluorescent dual-mode probe molecular solution;

[0009] b. Add the colorimetric fluorescent dual-mode probe molecule solution obtained in step a to a uniform volume of fluorescence cell to obtain the detection reagent;

[0010] c. After mixing and reacting the nerve agent simulant standard solution with the detection reagent obtained in step b, measure the changes in absorption spectrum and fluorescence spectrum.

[0011] Alternatively, the colorimetric fluorescent dual-mode probe molecule solution obtained in step a can be added to a nerve agent simulant solution, and the changes in absorption and fluorescence spectra can be measured.

[0012] Sensor chip fabrication:

[0013] A colorimetric fluorescent dual-mode probe was dispersed in an ethylene glycol solution, and then a polyurethane sponge was added to obtain a sensor chip. The obtained sensor chip was then placed in an atmosphere of diethyl chlorophosphate, a nerve agent simulant. Under 365 nm ultraviolet light, the fluorescence changed from strong blue fluorescence to weak green fluorescence, and under sunlight, it changed from colorless to yellow.

[0014] The present invention discloses a colorimetric fluorescent dual-mode probe for the application of diethyl chlorophosphate, a neurotoxin mimic. The probe molecule has the chemical name (2Z,2'Z)-3,3'-([1,1':4',1”-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile), and is a probe molecule with high solid-state quantum yield (quantum yield: 41.45%). It uses pyridine as the recognition site, and its chemical structure is as follows:

[0015]

[0016] The present invention relates to the application of a colorimetric fluorescent dual-mode probe in the neurotoxin mimic diethyl chlorophosphate. The synthesis method of this colorimetric fluorescent dual-mode probe molecule is carried out according to the following steps:

[0017] Step 1: Phenyboric acid and 2,5-dibromobenzene-1,4-dicarboxaldehyde were dissolved in nitrogen at a molar ratio of 3:1 in a mixture of toluene, ethanol and N,N-dimethylformamide at a volume ratio of 7:4:2. The mixture was stirred for 10 min, and 4 mL of 2M sodium carbonate and the catalyst tetrakis(triphenylphosphine)palladium were added. The mixture was stirred at 85 °C for 48 h and then the reaction was stopped. The mixture was extracted with dichloromethane, and the organic phase was concentrated under reduced pressure. The mixture was then washed with anhydrous ethanol to remove reaction byproducts. The eluted product was then dried to obtain compound 1.

[0018] Step 2: Dissolve compound 1 and 4-pyridine acetonitrile hydrochloride in 30 mL of anhydrous ethanol at a molar ratio of 2.4:1. After reacting at 40 °C for 24 h, stop the reaction, cool to room temperature, filter, separate the solid, wash three times with anhydrous ethanol, and dry under vacuum to obtain a colorimetric fluorescent dual-mode probe molecule with the chemical name (2Z,2'Z)-3,3'-([1,1':4',1”-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile);

[0019] Its synthetic route is as follows:

[0020]

[0021] The application of a colorimetric fluorescence dual-mode probe in the detection of the nerve agent mimic diethyl chlorophosphate (DCP) described in this invention utilizes the following principle:

[0022] Aggregated probe molecules, using pyridine as the recognition site, undergo a nucleophilic addition reaction with nerve agent mimics (DCPs), followed by hydrolysis that alters the intramolecular charge transfer of the probe molecules, resulting in changes in colorimetric and fluorescence spectra. Simultaneously, the increased polarity of the probe molecules after reacting with the nerve agent mimics (DCPs) promotes increased product solubility, leading to a decrease in fluorescence intensity. These combined effects result in fluorescence signal changes from strong blue to weak green fluorescence, colorimetric signal changes from colorless to yellow, and morphological changes from aggregated to partially aggregated, enabling rapid, sensitive, and specific detection of nerve agent mimics (DCPs).

[0023] The present invention relates to the application of a colorimetric fluorescent dual-mode probe in the nerve agent mimic diethyl chlorophosphate. The colorimetric fluorescent dual-mode probe can be used for rapid and qualitative detection of nerve agent mimics (DCP).

[0024] The application of the colorimetric fluorescent dual-mode probe of the present invention in the detection of the nerve agent mimic diethyl chlorophosphate, the detection steps of which are as follows:

[0025] a. Disperse 0.01 mmol of the probe in 100 mL of methanol solution to obtain a 0.1 mM probe molecule solution;

[0026] b. Add the probe molecule solution obtained in step a to a uniform volume of fluorescence cell to obtain a detection reagent for detecting DCP probe molecules;

[0027] c. After reacting the nerve agent mimic (DCP) standard solution with the probe molecules obtained in step b, the change in absorption spectrum was measured. The linear relationship between absorption intensity and nerve agent mimic (DCP) concentration was used for quantitative analysis. The detection limit calculated based on the formula 3σ / k was 0.29 μM.

[0028] d. After reacting the nerve agent mimic (DCP) standard solution with the probe molecules obtained in step b, the change in fluorescence spectrum was measured. The linear relationship between fluorescence intensity and nerve agent mimic (DCP) concentration was used for quantitative analysis. The detection limit calculated based on the formula 3σ / k was 0.95 nM.

[0029] Alternatively, the probe molecule solution obtained in step a can be added to a nerve agent mimic (DCP) solution, and the changes in absorption and fluorescence spectra can be measured. The intensity of the absorption and fluorescence spectra of the probe molecules increases / decreases with the increase of the concentration of nerve agent mimic (DCP), and the detection time is less than 5 seconds.

[0030] The sensor chip for detecting DCP described in this invention is obtained by dispersing a colorimetric fluorescent dual-mode probe in a 0.5 mM ethylene glycol solution and then adding a polyurethane sponge.

[0031] The sensor chip, when placed in a neurotoxin simulant (DCP) atmosphere, exhibits a fluorescence change from strong blue to weak green under 365nm ultraviolet light, and from colorless to yellow under sunlight, enabling real-time monitoring of DCP. This probe can detect DCP in a colorimetric and fluorescence dual-mode. The aggregated probe solution is colorless, exhibiting strong blue fluorescence under 365nm ultraviolet excitation and forming rod-like structures. After nucleophilic addition with DCP, hydrolysis leads to protonation of the pyridine recognition site, forming a pyridinium salt. This enhanced intramolecular charge transfer after detection results in a red shift in the colorimetric and fluorescence spectra, enabling DCP recognition. Simultaneously, the altered molecular structure increases product solubility, leading to decreased fluorescence and the aggregation of the probe into partially aggregated products. Compared to existing fluorescence detection techniques, the probe obtained in this invention enables colorimetric and fluorescence dual-mode detection of DCP, with a simple synthesis route, high sensitivity, good selectivity, and rapid identification, showing broad application prospects.

[0032] The present invention describes the application of a colorimetric fluorescent dual-mode probe in the nerve agent mimic diethyl chlorophosphate. The probe molecule solution and its sensing chip respond only to the nerve agent mimic (DCP), but do not respond to other similar analytes or common volatile organic solvents. This indicates that the probe molecule solution and its sensing chip have excellent selectivity for the nerve agent mimic (DCP). In particular, the constructed sensing chip achieves a detection limit of 1.7 ppb for the nerve agent mimic (DCP).

[0033] The present invention discloses the application of a colorimetric fluorescent dual-mode probe in the nerve agent mimic diethyl chlorophosphate. The colorimetric fluorescent dual-mode probe molecule and its sensing chip exhibit colorimetric and fluorescence responses to the nerve agent mimic (DCP), enabling colorimetric fluorescent dual-mode detection of the nerve agent mimic (DCP). Furthermore, it demonstrates fast response speed, low detection limit, and high selectivity for the nerve agent mimic (DCP). The constructed sensing chip can perform real-time visual monitoring of the nerve agent mimic (DCP) in the gas phase. Its advantages, such as low cost, high sensitivity, and good selectivity, make it easily applicable and widely promoted for timely on-site detection. Attached Figure Description

[0034] Figure 1 The one-dimensional proton NMR spectrum of the probe molecule in Example 1 of this invention, where the horizontal axis represents chemical shift and the vertical axis represents signal intensity;

[0035] Figure 2 The aggregation-induced emission characteristic curve (a) and solid-state quantum yield diagram (b) of the probe molecules in Example 2 of this invention;

[0036] Figure 3 The UV / Vis absorption spectrum changes between probe molecule (0.1 mM) methanol solution and nerve agent simulants (DCP) at different concentrations in Example 3 of this invention, where the horizontal axis is the spectral wavelength and the vertical axis is the absorption intensity; (a) is the UV / Vis absorption spectrum data of probe molecule detecting different DCP concentrations, and (b) is the linear curve data at 392 nm;

[0037] Figure 4 The fluorescence spectral changes between a 0.1 mM methanol solution of the probe molecule and different concentrations of nerve agent mimics (DCP) in Example 4 of this invention are shown, where the horizontal axis represents the spectral wavelength and the vertical axis represents the fluorescence intensity; (a) shows the fluorescence spectral data of the probe molecule detecting different DCP concentrations, and (b) shows the linear curve data at 530 nm.

[0038] Figure 5 The selective detection and recognition diagram of the probe molecule (0.1mM) methanol solution for nerve agent mimic (DCP) in Example 5 of the present invention, where the horizontal axis represents different interfering substances and the vertical axis represents the absorption intensity;

[0039] Figure 6 The selective detection and recognition diagram of nerve agent mimicry (DCP) by probe molecule (0.1 mM) methanol solution in Example 6 of the present invention, where the horizontal axis represents different interfering substances and the vertical axis represents fluorescence intensity;

[0040] Figure 7 The curves showing the changes in the absorption peak intensity at 392 nm and the fluorescence emission peak intensity at 456 nm (excitation wavelength 365 nm) of the probe molecule (0.1 mM) methanol solution with the addition of nerve agent mimic (DCP) (0.05 M) over time;

[0041] Figure 8 The images show the fluorescence color changes of the porous polymer constructed by the probe molecule (0.5 mM) ethylene glycol solution under ultraviolet light (365 nm) exposed to a nerve agent mimic (DCP) gas environment under a fluorescence inverted microscope and a morphology image under a scanning electron microscope.

[0042] Figure 9 In Example 9 of this invention, a porous polymer constructed from a probe molecule (0.5 mM) ethylene glycol solution was exposed to different concentrations of nerve agent simulant (DCP) gas environments under a UV lamp (365 nm) for colorimetric and fluorescence imaging. Detailed Implementation

[0043] The present invention will be further described in detail below through specific embodiments.

[0044] Example 1

[0045] Synthesis of colorimetric fluorescent dual-mode probe molecules:

[0046] Step 1: Phenyboric acid and 2,5-dibromobenzene-1,4-dicarboxaldehyde were dissolved in nitrogen at a molar ratio of 3:1 in a mixture of toluene, ethanol and N,N-dimethylformamide at a volume ratio of 7:4:2. The mixture was stirred for 10 min, and 4 mL of 2M sodium carbonate and the catalyst tetrakis(triphenylphosphine)palladium were added. The mixture was stirred at 85 °C for 48 h and then the reaction was stopped. The mixture was extracted with dichloromethane, and the organic phase was concentrated under reduced pressure. The organic phase was washed with ethanol to remove the reaction byproducts. The eluted product was then dried to obtain compound 1.

[0047] Step 2: Dissolve compound 1 and 4-pyridine acetonitrile hydrochloride in 30 mL of anhydrous ethanol at a molar ratio of 2.4:1. After reacting at 40 °C for 24 h, stop the reaction, cool to room temperature, filter, separate the solid, and dry under vacuum to obtain a colorimetric fluorescent dual-mode probe molecule. The chemical name of this probe molecule is (2Z,2'Z)-3,3'-([1,1':4',1”-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile);

[0048] Figure 1 For the 1H NMR spectrum of the colorimetric fluorescent dual-mode probe molecule: 1 H NMR (400MHz, Chloroform-d) δ (ppm): 8.69 (m, 4H), 8.34 (s, 2H), 7.78 (s, 2H), 7.54–7.33 (dq, 14H);

[0049] The colorimetric fluorescent dual-mode probe molecule obtained in Example 1 was placed in a mixture of dichloromethane and methanol, with methanol percentages of 0%, 10%, 30%, 50%, 60%, 70%, 80%, 90%, 99%, and 100%. Fluorescence spectral changes were measured under 365 nm UV excitation; the quantum yield of the fluorescent solid-state probe was measured under 395 nm UV excitation. Figure 2 As shown;

[0050] from Figure 2 It can be seen that the fluorescence of its probe molecule increases with the increase of unfavorable solvent, indicating that it has aggregation-induced emission properties and is an AIE molecule; and its solid-state quantum yield is as high as 41.45%. Figure 2 b).

[0051] Example 2

[0052] The colorimetric fluorescent dual-mode probe obtained in Example 1 was dispersed in 100 mL of methanol solution to obtain a 0.1 mM colorimetric fluorescent dual-mode probe molecular solution.

[0053] The obtained colorimetric fluorescent dual-mode probe molecule solution was added to a uniform volume of fluorescence cell to obtain the detection reagent.

[0054] After reacting the nerve agent mimic (DCP) standard solution with the obtained colorimetric fluorescent dual-mode probe molecule, the change in absorption spectrum was measured, and the linear relationship between absorption intensity and nerve agent mimic (DCP) concentration was used for quantitative analysis; the detection limit calculated based on the formula 3σ / k was 0.29 μM;

[0055] After reacting the nerve agent mimic (DCP) standard solution with the obtained colorimetric fluorescent dual-mode probe molecule, the change in fluorescence spectrum was measured, and the linear relationship between fluorescence intensity and nerve agent mimic (DCP) concentration was used for quantitative analysis; the detection limit calculated based on the formula 3σ / k was 0.95 nM;

[0056] Alternatively, the probe molecule solution obtained in step a can be added to a nerve agent mimic (DCP) solution, and the changes in absorption and fluorescence spectra can be measured. The intensity of the absorption and fluorescence spectra of the probe molecules increases / decreases with the increase of the concentration of nerve agent mimic (DCP), and the detection time is less than 5 seconds.

[0057] Example 3

[0058] The colorimetric fluorescent dual-mode probe obtained in Example 1 was dispersed in 100 mL of methanol solution to obtain a 0.1 mM probe molecule solution.

[0059] The obtained probe molecule solution is added to a uniform volume of fluorescence cell to obtain a detection reagent for detecting DCP probe molecules.

[0060] After reacting the obtained probe molecules with a standard solution of nerve agent mimic (DCP), the changes in absorption spectra were measured. Quantitative analysis was performed based on the linear relationship between absorption intensity and DCP concentration. The detection limit calculated using the formula 3σ / k was 0.29 μM. Figure 2 As shown;

[0061] from Figure 3 As can be seen from a, the probe molecule has very weak absorption, and its absorption intensity increases with the increase of the nerve agent mimic DCP content, indicating that it can be used to detect nerve agent mimic DCP; and there is a linear fit of 0.9872 at 392 nm, which can be used to infer the corresponding DCP concentration from the absorption intensity value. Figure 3 b);

[0062] Example 4

[0063] The colorimetric fluorescent dual-mode probe obtained in Example 1 was dispersed in 100 mL of methanol solution to obtain a 0.1 mM probe molecule solution.

[0064] The obtained probe molecule solution is added to a uniform volume of fluorescence cell to obtain a detection reagent for detecting DCP probe molecules.

[0065] The obtained 0.1 mM probe molecule solution was subjected to fluorescence detection analysis of the nerve agent mimic DCP;

[0066] After reacting a standard solution of nerve agent mimic (DCP) with the obtained colorimetric fluorescent dual-mode probe molecule, the changes in fluorescence spectrum were measured. Quantitative analysis was performed based on the linear relationship between fluorescence intensity and DCP concentration. The fluorescence intensity of the probe molecule increased with increasing DCP concentration, indicating the presence of DCP. Figure 4 a); and there is a linear fit of 0.9956 at 456 nm, which can be used to infer the corresponding DCP concentration from the fluorescence intensity value. Figure 4 b) The detection limit calculated based on the formula 3σ / k is 0.95 nM;

[0067] Figure 3 and Figure 4 The results showed that the changes in the UV / Vis absorption and fluorescence spectra of the colorimetric fluorescent dual-mode probe molecule solution exhibited a linear relationship with the changes in DCP concentration. Therefore, this type of probe molecule has excellent ability to detect DCP, and its fluorescence detection limit is as low as 0.95 nM.

[0068] Example 5

[0069] Selective detection of DCP by probe molecules:

[0070] The selectivity of the colorimetric fluorescent dual-mode probe molecule for nerve agent mimics (DCP) was evaluated using the 0.1 mM colorimetric fluorescent dual-mode probe molecule solution prepared in Example 3. Figure 5 and Figure 6 The results show the changes in the UV / Vis absorption and fluorescence peak values ​​of the colorimetric fluorescent dual-mode probe molecule when various common interfering substances are added to the solution: DMMP, DIMP, TEP, TBP, tetrahydrofuran, benzene, glacial acetic acid, propylene glycol methyl ether, acetone, xylene, dichloromethane, toluene, formaldehyde, phosphoric acid, ethanol, ethyl acetate, and n-hexane. For example, when structural analogs of common nerve agent mimics or common volatile organic solvents in the laboratory are added, the UV / Vis absorption and fluorescence peak values ​​of the colorimetric fluorescent dual-mode probe solution show almost no change. However, after adding a nerve agent mimic (DCP), the UV / Vis absorption peak value is significantly enhanced and the fluorescence peak value drops sharply, indicating that the colorimetric fluorescent dual-mode probe molecule has a good selective recognition function for nerve agent mimics (DCP).

[0071] Example 6

[0072] UV / Vis absorption and fluorescence peak intensities versus time in the detection of nerve agent mimics (DCP) using a colorimetric fluorescent dual-mode probe:

[0073] The UV / Vis absorption and fluorescence peak intensity changes of the probe molecules against the nerve agent mimic (DCP) were evaluated using the 0.1 mM colorimetric fluorescent dual-mode probe molecule solution prepared in Example 3. Figure 7 This describes the relationship between the changes in peak intensity of the UV / Vis absorption and fluorescence spectra and time when using a colorimetric fluorescence dual-mode probe molecule to detect nerve agent mimics (DCP). Figure 7 The results show that the colorimetric fluorescent dual-mode probe molecule can achieve a stable response within 5 seconds when detecting nerve agent mimics (DCP), demonstrating the ability to rapidly detect nerve agent mimics (DCP). Therefore, this colorimetric fluorescent dual-mode probe molecule has the ability to rapidly detect nerve agent mimics (DCP) and exhibits good detection performance.

[0074] Example 7

[0075] The colorimetric fluorescent dual-mode probe molecule obtained in Example 1 was used to detect nerve agent mimic (DCP) vapor:

[0076] Sensor chip fabrication:

[0077] The colorimetric fluorescent dual-mode probe obtained in Example 1 was dispersed in an ethylene glycol solution to prepare a 0.5 mM colorimetric fluorescent dual-mode probe molecular solution. A polyurethane sponge was then added to obtain a sensor chip. The sensor chip was then placed in 60 ppm of diethyl chlorophosphate vapor (a nerve agent simulant) for 94 s, and its morphological changes before and after detection were observed under an inverted fluorescence microscope and a scanning electron microscope. Figure 8 As shown, when the sensor chip is exposed to nerve agent mimic (DCP) vapor, due to the effective adsorption and specific recognition of the nerve agent mimic (DCP) by the porous polymer matrix loaded with probes, the changes in fluorescence from colorless to yellow and from strong blue to weak green under sunlight can be clearly observed. Furthermore, the needle-like probes, which are about 30 mm in diameter and aggregated on the porous polymer framework, depolymerize into dispersed spheres of several hundred micrometers after encountering nerve agent mimic (DCP) vapor, proving that this probe can recognize nerve agent mimic (DCP) in colorimetric fluorescence dual-mode and exhibit morphological changes.

[0078] Example 8

[0079] The sensor chip obtained in Example 7 was used to detect nerve agent simulant DCP vapor:

[0080] The sensor chip obtained in Example 7 was placed in nerve agent mimic (DCP) vapor at concentrations of 0, 5, 30, 50, 100, 110, 330, 675, 1215, and 4200 for 94 seconds, and its color change and fluorescence were photographed using a microscope (under 365 nm ultraviolet light excitation). Figure 9As shown, the sensor chip is colorless and exhibits strong blue fluorescence under 365nm ultraviolet light excitation. As the concentration of nerve agent mimic (DCP) increases, it gradually turns yellow, and after the strong blue fluorescence weakens under 365nm ultraviolet light excitation, weak green fluorescence appears. The obvious colorimetric fluorescence dual-mode signal change is beneficial for the specific identification of nerve agent mimic (DCP).

Claims

1. The application of a colorimetric fluorescent dual-mode probe in the neurotoxin mimic diethyl chlorophosphate, characterized in that, The probe molecule has the chemical name (2Z,2'Z)-3,3'-([1,1':4',1''-terphenyl]-2',5'-substituent)bis(2-(pyridin-4-yl)acrylonitrile). The probe molecule is used to detect the nerve agent mimic diethyl chlorophosphate. The detection steps are as follows: a. Disperse 0.01 mmol of the probe in 100 mL of methanol solution to obtain a 0.1 mM probe molecule solution; b. Add the probe molecule solution obtained in step a to a uniform volume of fluorescence cell to obtain a detection reagent for detecting probe molecules of nerve agent mimics; c. After reacting the nerve agent simulant standard solution with the probe molecules obtained in step b, the change in absorption spectrum was measured, and the linear relationship between the absorption intensity and the nerve agent simulant concentration was used for quantitative analysis; the detection limit calculated based on the formula 3σ / k was 0.29 µM; d. After reacting the standard solution of the nerve agent simulant with the probe molecules obtained in step b, the change in fluorescence spectrum was measured. The linear relationship between fluorescence intensity and nerve agent simulant concentration was used for quantitative analysis. The detection limit calculated based on the formula 3σ / k was 0.95 nM. Under 365 nm ultraviolet light, the fluorescence changed from strong blue fluorescence to weak green fluorescence, and under sunlight, it changed from colorless to yellow. Alternatively, the probe molecule solution obtained in step a can be added to a nerve agent simulant solution, and the changes in absorption and fluorescence spectra can be measured. The intensity of the absorption and fluorescence spectra of the probe molecules increases / decreases with the increase of the concentration of the nerve agent simulant, and the detection time is less than 5 s.

Images