A 2-(2-aminophenyl)benzothiazole-based d-a type organic fluorescent small molecule, a preparation method and application in phosgene and sarin detection

Abstract

The application provides a D-A type organic fluorescent small molecule based on 2-(2-aminophenyl) benzothiazole, a preparation method and application in phosgene and sarin detection, and belongs to the technical field of fluorescent sensing. The D-A type organic fluorescent small molecule provided by the application is composed of 2-(2-aminophenyl) benzothiazole and an electron-donating group. 2-(2-aminophenyl) benzothiazole serves as an electron-accepting group, and after the introduction of the electron-donating group, an intramolecular charge transfer state can be formed, thereby constructing the D-A type organic fluorescent small molecule. Meanwhile, 2-(2-aminophenyl) benzothiazole serves as a recognition site for sensing reaction and interacts with phosgene and a nerve toxicant molecule through different sensing mechanisms, thereby exhibiting completely different fluorescence responses, so that the purpose of integrated detection of multiple hazardous substances is achieved. After the material is made into a sensor, efficient fluorescence colorimetric detection of trace phosgene and nerve toxicant molecules in liquid and gas phases can be realized, and the material has the advantages of high sensitivity, good selectivity and strong anti-interference ability. Further, by combining a smart phone to perform RGB analysis on the image of the filter paper fluorescent sensor of the material, the RGB value of the image can be output in real time, thereby realizing visual quantitative fluorescence detection of phosgene and nerve toxicant molecules.

Description

Technical Field

[0001] This invention relates to the field of fluorescence sensing technology, and in particular to a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, its preparation method, and its application in the detection of phosgene and sarin. Background Technology

[0002] Chemical warfare agents are a class of highly toxic and lethal chemical substances. They include asphyxiating agents, nerve agents, and vesicants. Asphyxiating agents (phosgene) and nerve agents (sarin) are the earliest and most commonly used chemical warfare agents. It is noteworthy that phosgene, as an indispensable raw material in the industrial production of pesticides, pharmaceuticals, dyes, and polymers, is a readily available chemical. Therefore, there is an urgent need to develop rapid, efficient, highly sensitive, highly selective, and portable technologies suitable for on-site detection of phosgene and sarin.

[0003] Currently, conventional methods for detecting phosgene and sarin mainly include gas chromatography, electrochemical methods, mass spectrometry, ion mobility spectrometry, and interferometry. However, these techniques rely on fixed equipment, and their application is limited by factors such as operational complexity, time consumption, and poor portability. In contrast, fluorescence detection has become an ideal choice due to its advantages of real-time accuracy, high selectivity, high sensitivity, and simple operation. Furthermore, fluorescence sensors mounted on filter paper are increasingly favored due to their low cost, portability, and environmental friendliness.

[0004] Currently, researchers have developed various fluorescent sensors for detecting phosgene and sarin. However, most fluorescent sensors only work for a single phosgene or sarin, not both. Fluorescent sensors with different fluorescence responses to multiple analytes are more cost-effective than those that identify a single analyte. To our knowledge, only a few fluorescent sensors have been reported for the simultaneous detection of phosgene and sarin, and these rely on "enhanced" fluorescence signals, making their measurement accuracy susceptible to external factors. Furthermore, the human eye has limited perception of changes in fluorescence intensity, making visual detection difficult. In this context, ratiometric fluorescent sensors reduce systematic errors and external interference through their internal calibration and visualization properties. However, to date, no ratiometric fluorescent sensors have been reported for the simultaneous and accurate identification and visual detection of phosgene and sarin. Summary of the Invention

[0005] In view of this, the present invention aims to provide a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, its preparation method, and its application in the detection of phosgene and sarin. The DA-type organic fluorescent small molecule provided by the present invention can achieve single or integrated fluorescence detection of phosgene and sarin and / or diethyl chlorophosphate (DCP) in high-performance liquid chromatography and gas chromatography.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, having the structure shown in Formula I:

[0008]

[0009] In Equation I, R is

[0010] Preferably, it has the structure shown in any one of Formulas II to V:

[0011]

[0012] This invention provides a method for preparing the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, comprising the following steps:

[0013] Compounds having the structure shown in Formula A, compound B, catalyst, solvent and basic reagent were mixed and subjected to Suzuki-Miyaura coupling reaction to obtain a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole having the structure shown in Formula I;

[0014] In formula A, X is Cl, Br, or I;

[0015] The compound B has the structures shown in formulas B1 to B10:

[0016]

[0017] In formulas B1 to B10, Y is a borate group or a borate ester group.

[0018] The present invention provides a liquid-phase fluorescence sensor comprising a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole and an organic solvent, wherein the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is the aforementioned DA-type organic fluorescent small molecule.

[0019] This invention provides the application of the above-mentioned liquid phase fluorescence sensor in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents;

[0020] The asphyxiating agent is phosgene;

[0021] The nerve agent is sarin and / or diethyl chlorophosphate;

[0022] Phosgene, sarin, and / or diethyl chlorophosphate are detected in liquid form.

[0023] The present invention provides a filter paper fluorescence sensor, comprising filter paper and a fluorescent material loaded on the surface of the filter paper, wherein the fluorescent material comprises the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole.

[0024] This invention provides the application of the above-mentioned filter paper fluorescence sensor in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents;

[0025] The asphyxiating agent is phosgene;

[0026] The nerve agent is sarin and / or diethyl chlorophosphate;

[0027] Phosgene, sarin, and / or diethyl chlorophosphate are detected in gaseous form.

[0028] This invention provides a standard fluorescent card for detecting chemical warfare agents, prepared from the above-mentioned filter paper fluorescent sensor, wherein the chemical warfare agents include asphyxiating agents and / or nerve agents;

[0029] The asphyxiating agents include phosgene;

[0030] The nerve agents include sarin and / or diethyl chlorophosphate;

[0031] Phosgene, sarin, and / or diethyl chlorophosphate are detected in gaseous form.

[0032] Preferably, the method for detecting chemical warfare agents includes visual quantitative fluorescence detection of chemical warfare agents, specifically, visual quantitative fluorescence detection of chemical warfare agents by combining the RGB values ​​of fluorescence images output in real time by a smartphone.

[0033] This invention provides the application of the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole in the integrated fluorescence detection of multiple chemical warfare agents, wherein the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is the above-mentioned DA-type organic fluorescent small molecule; the multiple chemical warfare agents include asphyxiating agents and nerve agents.

[0034] The asphyxiating agents include phosgene;

[0035] The nerve agents include sarin and / or diethyl chlorophosphate.

[0036] This invention provides a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, having the structure shown in Formula I. The entire molecular backbone of the DA-type organic fluorescent small molecule provided by this invention consists of an electron acceptor (2-(2-aminophenyl)benzothiazole) and an electron donor (i.e., the R group in Formula I). ​​This type of DA-type organic fluorescent small molecule material has the following beneficial effects:

[0037] (1) Using 2-(2-aminophenyl)benzothiazole as the main luminescent building unit and as an electron acceptor group, by introducing electron donor groups such as tetraphenylethylene and triphenylamine, an intramolecular charge transfer state (ICT) can be formed to construct a DA-type organic fluorescent small molecule, and the degree of ICT can be effectively adjusted to regulate its emission wavelength.

[0038] (2) 2-(2-aminophenyl)benzothiazole has a rigid planar conjugated structure. After connecting an electron donor with a twisted configuration through covalent bonds, it reduces the intermolecular interaction and ensures high luminescence efficiency. On the other hand, when it is used as a guest material to prepare a filter paper fluorescence sensor, the twisted angle between the donor and acceptor in the molecule helps to increase the molecular cavity, so that the DA-type organic fluorescent small molecule can fully contact the analyte, thereby improving its detection performance.

[0039] (3) The amino and aromatic nitrogen atoms on the 2-(2-aminophenyl)benzothiazole group have strong nucleophilicity and can undergo two carbamylation reactions with phosgene to form cyclic products, which can realize efficient and rapid detection of trace phosgene through fluorescence / chromogenic dual channels.

[0040] (4) The amino and aromatic nitrogen atoms on the 2-(2-aminophenyl)benzothiazole group have strong nucleophilic ability and can react with sarin and / or diethyl chlorophosphate, which have electrophilic properties, to produce a stronger ICT process, which ultimately leads to a red shift in the emission spectrum, enabling the visual fluorescence detection of sarin and / or diethyl chlorophosphate.

[0041] (5) Since the 2-(2-aminophenyl)benzothiazole group is connected to the electron donor group, its nucleophilic ability is further enhanced, thereby further improving the detection sensitivity and response time of the DA-type organic fluorescent small molecule for phosgene and sarin and / or diethyl chlorophosphate (DCP).

[0042] (6) The DA-type organic fluorescent small molecules exhibit completely different fluorescence responses through different sensing mechanisms, namely, generating new cyclic chemical substances after reacting with phosgene, and generating products with strong ICT properties after reacting with sarin and / or diethyl chlorophosphate (DCP), thus achieving the purpose of integrated detection of phosgene and sarin and / or diethyl chlorophosphate (DCP).

[0043] This invention prepares a liquid-phase fluorescence sensor, a filter paper fluorescence sensor, and a standard fluorescence card for detecting chemical warfare agents based on the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole. It can realize single or integrated fluorescence detection of phosgene and sarin and / or diethyl chlorophosphate (DCP) in high-performance liquid and gas phases. It can also be combined with a smartphone to output the RGB values ​​of the filter paper fluorescence sensor image based on the DA-type organic fluorescent small molecule in real time, further realizing the visualized quantitative fluorescence detection of phosgene and sarin and / or diethyl chlorophosphate (DCP) in gas phase. Attached Figure Description

[0044] Figure 1 The ultraviolet absorption and fluorescence emission spectra of BTTPE in dichloromethane are shown.

[0045] Figure 2 The ultraviolet absorption spectrum of the solution after adding TEA / triphosgene to the BTTPE liquid phase fluorescence sensor;

[0046] Figure 3 The fluorescence emission spectrum and linear relationship curve of concentration-fluorescence intensity ratio of the solution after adding TEA / triphosgene to the BTTPE liquid phase fluorescence sensor;

[0047] Figure 4 Bar chart showing the UV absorption spectrum and fluorescence intensity ratio of the BTTPE liquid phase fluorescence sensor after adding different interfering substances;

[0048] Figure 5 A bar chart showing the fluorescence intensity ratio of a BTTPE liquid phase fluorescence sensor after adding different interfering substances to a mixed solution of TEA / triphosgene;

[0049] Figure 6 The UV absorption spectrum of the solution after adding DCP to the BTTPE liquid phase fluorescence sensor;

[0050] Figure 7 Bar chart showing fluorescence emission spectra and fluorescence intensity ratios after adding different concentrations of DCP to a BTTPE liquid-phase fluorescence sensor;

[0051] Figure 8 Bar chart showing the UV absorption spectrum and fluorescence intensity ratio of the BTTPE liquid phase fluorescence sensor after adding different interfering substances;

[0052] Figure 9 A bar chart showing the fluorescence intensity ratio of a BTTPE liquid phase fluorescence sensor after adding mixed solutions of different interfering substances and DCP;

[0053] Figure 10 Visualized quantitative detection results of phosgene and anti-interference detection results of BTTPE filter paper fluorescence sensor;

[0054] Figure 11 The results of DCP visualization and quantitative detection and anti-interference detection of BTTPE filter paper fluorescence sensor;

[0055] Figure 12 Fluorescence emission spectra of solutions containing TEA / triphosgene and DCP were obtained for the BTTPE liquid phase fluorescence sensor, respectively.

[0056] Figure 13 Fluorescence emission spectra of solutions containing TEA / triphosgene and DCP were obtained for the BTTPA liquid phase fluorescence sensor, respectively.

[0057] Figure 14 Fluorescence emission spectra of solutions containing TEA / triphosgene and DCP were obtained for the BT3PCz liquid phase fluorescence sensor, respectively.

[0058] Figure 15 Fluorescence emission spectra of solutions containing TEA / triphosgene and DCP were obtained for the BTPCz liquid phase fluorescence sensor. Detailed Implementation

[0059] This invention provides a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, having the structure shown in Formula I:

[0060]

[0061] In Equation I, R is

[0062] In this invention, the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole preferably has the structure shown in any one of Formulas II to V:

[0063]

[0064] This invention provides a method for preparing the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, comprising the following steps:

[0065] Compounds having the structure shown in Formula A, compound B, catalyst, solvent and basic reagent were mixed and subjected to Suzuki-Miyaura coupling reaction to obtain a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole having the structure shown in Formula I;

[0066] In formula A, X is Cl, Br, or I;

[0067] The compound B has the structures shown in formulas B1 to B10:

[0068]

[0069] In formulas B1 to B10, Y is a borate group or a borate ester group.

[0070] In this invention, unless otherwise specified, all raw materials required for preparation are commercially available products well known to those skilled in the art.

[0071] In this invention, the catalyst preferably comprises an organopalladium catalyst, which is preferably one or both of tetra(triphenylphosphine)palladium and bis(triphenylphosphine)palladium dichloride, more preferably tetra(triphenylphosphine)palladium.

[0072] In this invention, the alkaline reagent preferably includes one or both of potassium carbonate and potassium phosphate, more preferably potassium carbonate; the alkaline reagent is preferably added in the form of an aqueous solution, and the concentration of the aqueous solution is preferably 2 mol / L.

[0073] In this invention, the molar ratio of the compound having the structure shown in Formula A, the compound having the structure shown in Formula B, the catalyst, and the basic reagent is preferably 1:(1-5):(0.04-0.1):(8-30), more preferably 1:1.2:0.05:(10-20).

[0074] This invention does not have any special requirements for the organic solvent; any organic solvent well known to those skilled in the art can be used. As a specific embodiment of this invention, the organic solvent is preferably a mixture of toluene and ethanol, with the volume ratio of toluene to ethanol in the mixture preferably being (2-5):1, more preferably (3-4):1. This invention does not have any special requirements for the amount of organic solvent used; it is sufficient to completely dissolve the reaction raw materials.

[0075] In this invention, the preferred method of mixing is:

[0076] (a) A compound having the structure shown in Formula A, a compound having the structure shown in Formula B, and a basic reagent are mixed to obtain a first mixed system;

[0077] (b) After freezing and vacuuming the first mixture in sequence, a catalyst and an organic solvent are added to it under a protective atmosphere to obtain a second mixture.

[0078] (c) The second mixture system is frozen and vacuumed in sequence.

[0079] In this invention, the freezing in steps (b) and (c) is preferably liquid nitrogen freezing; the method of vacuuming in steps (b) and (c) is not particularly limited, and any vacuuming method well known in the art can be used; each step (b) and (c) is considered an operation consisting of one freezing and one vacuuming operation, and the operations are repeated, preferably three times each, with a preferred freezing time of 10 minutes and a preferred vacuuming time of 5 minutes. By employing the above-described feeding sequence and pretreatment methods of freezing and vacuuming, this invention can remove oxygen from the reaction system as much as possible, thereby avoiding the oxidative deactivation of the palladium catalyst and providing favorable conditions for the Suzuki-Miyaura coupling reaction.

[0080] In this invention, the Suzuki-Miyaura coupling reaction is preferably carried out under a protective atmosphere, preferably argon. In this invention, the temperature of the Suzuki-Miyaura coupling reaction is 85–90°C, more preferably 90°C; the time is preferably 24–48 h, more preferably 36–48 h.

[0081] Following the Suzuki-Miyaura coupling reaction, the present invention preferably performs post-treatment on the resulting coupling reaction solution, which preferably includes the following steps:

[0082] After cooling the coupling reaction solution to room temperature, it was extracted with water and dichloromethane, and the organic phase was collected.

[0083] The organic phase was successively dried and rotary evaporated to obtain a crude product;

[0084] The crude product was purified by column chromatography to obtain the DA-type organic fluorescent small molecule.

[0085] In this invention, the drying reagent used is preferably anhydrous magnesium sulfate; the rotary evaporation is used to remove organic solvents. In this invention, the eluent used for column chromatography purification is preferably dichloromethane and petroleum ether, and the volume ratio of dichloromethane to petroleum ether is preferably (1-5):(1-20), more preferably (1-3):(1-9).

[0086] This invention provides the application of the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents;

[0087] The asphyxiating agents include phosgene;

[0088] The nerve agents include sarin and / or diethyl chlorophosphate.

[0089] The DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole provided by this invention has good solubility in organic solvents, which is beneficial for the preparation of liquid phase fluorescence sensors and filter paper fluorescence sensors.

[0090] This invention provides a liquid-phase fluorescence sensor comprising a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole and an organic solvent, wherein the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is the aforementioned DA-type organic fluorescent small molecule. In this invention, the organic solvent preferably comprises one of cyclohexane, tetrahydrofuran, dichloromethane, acetonitrile, and toluene, more preferably dichloromethane.

[0091] In this invention, the concentration of the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole in the liquid-phase fluorescence sensor is preferably 0.5–2 mg / mL, more preferably 1–1.5 mg / mL. This invention does not impose any special requirements on the preparation method of the liquid-phase fluorescence sensor; the DA-type organic fluorescent small molecule can be directly dissolved in an organic solvent.

[0092] This invention provides the application of the above-mentioned liquid-phase fluorescence sensor in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents; the asphyxiating agents include phosgene; the nerve agents include sarin and / or diethyl chlorophosphate. In this invention, the phosgene, sarin, and / or diethyl chlorophosphate are in liquid form.

[0093] In this invention, the method for using the liquid-phase fluorescence sensor to detect chemical warfare agents preferably includes the following steps:

[0094] The test liquid is added to the liquid phase fluorescence sensor, and the changes in the absorption spectrum, color, fluorescence emission spectrum, and fluorescence color of the liquid phase fluorescence sensor are observed.

[0095] In this invention, if the absorption peak of the liquid fluorescence sensor generates new absorption peaks at 458 nm and 472 nm, and the color of the solution changes from colorless to yellow; the original maximum fluorescence emission peak (compared to the original maximum fluorescence emission peak without phosgene) gradually weakens and generates a new emission peak at 516 nm, accompanied by a significant change in fluorescence color, that is, the solution color and fluorescence change simultaneously, then it is determined that the test liquid contains phosgene.

[0096] In this invention, if the absorption peak of the liquid fluorescence sensor generates a new absorption peak at 490 nm; the original maximum fluorescence emission peak (compared to the original maximum fluorescence emission peak without sarin and / or diethyl chlorophosphate) gradually weakens or generates a new emission peak at 610 nm, accompanied by a significant color change or quenching response in the fluorescence color, then it is determined that the test solution contains sarin and / or diethyl chlorophosphate.

[0097] The color changes and fluorescence color changes of the liquid-phase fluorescence sensor can be directly observed with the naked eye, and the changes in the absorption spectrum and fluorescence emission spectrum of the liquid-phase fluorescence sensor can be detected using an ultraviolet absorption spectrometer and a fluorescence emission spectrometer. The liquid-phase fluorescence sensor of this invention exhibits distinctly different fluorescence responses to phosgene, sarin, and / or diethyl chlorophosphate, thus achieving efficient and integrated fluorescence detection of phosgene, sarin, and / or diethyl chlorophosphate in the liquid phase.

[0098] The present invention provides a filter paper fluorescence sensor, comprising filter paper and a fluorescent material loaded on the surface of the filter paper, wherein the fluorescent material comprises the above-mentioned DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole.

[0099] The present invention does not impose any special limitations on the filter paper; commercially available products well known in the art can be selected.

[0100] In this invention, the method for preparing the filter paper fluorescence sensor preferably includes the following steps:

[0101] A DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is dissolved in an organic solvent to obtain a solution containing the DA-type organic fluorescent small molecule; filter paper is immersed in the solution containing the DA-type organic fluorescent small molecule and then air-dried to obtain the filter paper fluorescent sensor.

[0102] In this invention, the organic solvent preferably includes one of cyclohexane, tetrahydrofuran, dichloromethane, acetonitrile, and toluene, and more preferably dichloromethane.

[0103] In this invention, the concentration of the solution containing DA-type organic fluorescent small molecules is preferably 0.1–2 mg / mL, more preferably 0.5–0.8 mg / mL. In this invention, the soaking time is preferably 10–30 s.

[0104] This invention provides the application of the above-mentioned filter paper fluorescence sensor in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents; the asphyxiating agents include phosgene; the nerve agents include sarin and / or diethyl chlorophosphate. In this invention, the phosgene, sarin, and / or diethyl chlorophosphate are in a gaseous state.

[0105] In this invention, the method for using the filter paper fluorescence sensor to detect chemical warfare agents preferably includes the following steps:

[0106] The filter paper fluorescence sensor is placed in the gas to be tested, and the color change and fluorescence color change of the filter paper fluorescence sensor are observed. Under natural light, the color change of the filter paper fluorescence sensor can be directly observed with the naked eye. When the filter paper fluorescence sensor is irradiated with a 365nm handheld ultraviolet lamp, the fluorescence color change of the filter paper fluorescence sensor can be directly observed with the naked eye.

[0107] In this invention, if the filter paper fluorescence sensor changes from white to yellow, and the fluorescence changes from blue to green, it is determined that the gas to be tested contains phosgene. If the fluorescence of the filter paper fluorescence sensor changes from blue to magenta or the fluorescence is completely quenched, it is determined that the gas to be tested contains sarin and / or diethyl chlorophosphate.

[0108] The filter paper fluorescence sensor of the present invention exhibits clearly distinguishable fluorescence color changes for phosgene, sarin, and / or diethyl chlorophosphate, thus achieving the goal of efficient and integrated fluorescence detection of phosgene, sarin, and / or diethyl chlorophosphate in the gas phase.

[0109] This invention provides a standard fluorescent card for detecting chemical warfare agents, prepared from the aforementioned filter paper fluorescent sensor. The invention prepares the standard fluorescent card by placing the filter paper fluorescent sensor in atmospheres of different concentrations of phosgene, sarin, and / or diethyl chlorophosphate. By comparing the fluorescence colors on different fluorescent cards under a 365nm handheld ultraviolet lamp, different concentrations of phosgene, sarin, and / or diethyl chlorophosphate can be distinguished, enabling real-time, rapid, and accurate on-site determination of the concentrations of phosgene, sarin, and / or diethyl chlorophosphate. This has significant commercial application value and importance.

[0110] This invention provides the application of the aforementioned standard fluorescent card for detecting chemical warfare agents in the detection of chemical warfare agents, including asphyxiating agents and / or nerve agents; the asphyxiating agent is phosgene; the nerve agent is sarin and / or diethyl chlorophosphate. In this invention, the application includes the visual quantitative fluorescence detection of chemical warfare agents, specifically, the visual quantitative fluorescence detection of chemical warfare agents is performed by combining the RGB values ​​of the fluorescence image output in real time by a smartphone.

[0111] This invention provides a visual quantitative fluorescence detection method for chemical warfare agents, comprising the following steps:

[0112] The above-mentioned filter paper fluorescence sensor is placed in the gas to be tested, and the fluorescence image of the filter paper fluorescence sensor is acquired using a smartphone and the RGB value of the fluorescence image is output in real time to obtain the R / B value, R / G value or G / B value.

[0113] The concentration of chemical warfare agent in the gas to be tested is obtained based on the R / B value, R / G value, or G / B value and a predetermined standard curve; the standard curve is a linear relationship curve between the R / B value, R / G value, or G / B value and the concentration of chemical warfare agent.

[0114] In this invention, the RGB values ​​are the values ​​of the red, green, and blue channels; the R / B value is the ratio of the red channel to the blue channel; the R / G value is the ratio of the red channel to the green channel; and the G / B value is the ratio of the green channel to the blue channel.

[0115] In this invention, the linear detection range of the standard curve is preferably 16–132 ppm or 5–40 ppm; the detection limit of phosgene is preferably 0.29 ppm; and the detection limit of sarin and / or diethyl chlorophosphate is preferably 0.49 ppm.

[0116] The following examples illustrate the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, its preparation method, and its application in phosgene and sarin detection, but these should not be construed as limiting the scope of protection of this invention.

[0117] Example 1

[0118] The synthetic route for the synthesis of DA-type organic fluorescent small molecules based on 2-(2-aminophenyl)benzothiazole is as follows:

[0119]

[0120] Under argon protection, 2-(benzothiazol-2-yl)-4-bromoaniline (184 mg, 0.6 mmol), 1-(4-phenylboronic acid pinacol ester)-1,2,2-tristyrene (229 mg, 0.5 mmol), tetra(triphenylphosphine)palladium (29 mg, 0.025 mmol), toluene (20 mL), potassium carbonate aqueous solution (2 mol / L, 12 mL), and ethanol (6 mL) were added to 100 mL double-necked flasks, and the mixture was heated to reflux at 90 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction mixture was extracted with water and dichloromethane. The aqueous phase was discarded, and the organic phase was collected. The organic phase was dried with anhydrous magnesium sulfate, and the organic solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography (dichloromethane-petroleum ether, volume ratio 1:2) to obtain a yellow solid product (200 mg, 72%), which is a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, denoted as BTTPE.

[0121] The BTTPE NMR data prepared in this embodiment are as follows:

[0122] 1¹H NMR (500MHz, DMSO) δ 8.09 (d, J = 7.8Hz, 1H), 8.03 (d, J = 8.0Hz, 1H), 7.79 (d, J = 2.0Hz, 1H), 7.53 (dd, J = 13.7, 5.3Hz, 2H), 7.49–7.42 (m, 5H), 7.21–7.09 (m, 9H), 7.06–7.01 (m, 6H), 6.97 (dd, J = 10.7, 7.7Hz, 3H). Mass spectrometry molecular ion peak: 556.5861; theoretical molecular weight: 556.1973. Elemental analysis theoretical value: C 39 H 28 N₂S: C, 84.14; H, 5.07; N, 5.03; Actual elemental analysis values: C, 84.71; H, 5.13; N, 5.03.

[0123] Example 2

[0124] The synthetic route for the synthesis of DA-type organic fluorescent small molecules based on 2-(2-aminophenyl)benzothiazole is as follows:

[0125]

[0126] Under argon protection, 2-(benzothiazol-2-yl)-4-bromoaniline (305 mg, 1 mmol), 4-(diphenylamino)phenylboronic acid (434 mg, 1.5 mmol), tetra(triphenylphosphine)palladium (58 mg, 0.05 mmol), toluene (12 mL), potassium carbonate aqueous solution (2 mol / L, 8 mL), and ethanol (4 mL) were added separately to 50 mL double-necked flasks, and the mixture was heated to reflux at 90 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction mixture was extracted with water and dichloromethane. The aqueous phase was discarded, and the organic phase was collected. The organic phase was dried over anhydrous magnesium sulfate, and the organic solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography (dichloromethane-petroleum ether, volume ratio 1:3) to obtain a yellow solid product (300 mg, 64%), which is a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazolium, denoted as BTTPA.

[0127] The BTTPA NMR data prepared in this embodiment are as follows:

[0128] 1¹H NMR (500MHz, DMSO) δ 8.11 (d, J = 7.8Hz, 1H), 8.04 (d, J = 8.1Hz, 1H), 7.82 (s, 1H), 7.59–7.51 (m, 4H), 7.47–7.42 (m, 3H), 7.32 (t, J = 7.8Hz, 4H), 7.06 (t, J = 7.9Hz, 8H), 6.99 (d, J = 8.6Hz, 1H). Mass spectrometry molecular ion peak: 469.1099; theoretical molecular weight: 469.1613. Elemental analysis theoretical value: C 31 H 23 N3S: C, 79.29; H, 4.94; N, 8.95; Actual elemental analysis values: C, 79.96; H, 5.06; N, 8.87.

[0129] Example 3

[0130]

[0131] The synthetic route for the synthesis of DA-type organic fluorescent small molecules based on 2-(2-aminophenyl)benzothiazole is as follows:

[0132] Under argon protection, 2-(benzothiazol-2-yl)-4-bromoaniline (184 mg, 0.6 mmol), N-phenyl-3-carbazoleboric acid (208 mg, 0.72 mmol), tetra(triphenylphosphine)palladium (34 mg, 0.03 mmol), toluene (20 mL), potassium carbonate aqueous solution (2 mol / L, 12 mL), and ethanol (6 mL) were added separately to 100 mL double-necked flasks, and the mixture was heated to reflux at 90 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction mixture was extracted with water and dichloromethane. The aqueous phase was discarded, and the organic phase was collected. The organic phase was dried over anhydrous magnesium sulfate, and the organic solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography (dichloromethane-petroleum ether, volume ratio 1:1) to obtain a yellow solid product (147 mg, 53%), which is a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazolium, denoted as BT3PCz.

[0133] The BT3PCz NMR data prepared in this embodiment are as follows:

[0134] 1¹H NMR (500MHz, DMSO) δ 8.54 (d, J = 1.4Hz, 1H), 8.39 (d, J = 7.7Hz, 1H), 8.12 (d, J = 7.8Hz, 1H), 8.06 (d, J = 8.1Hz, 1H), 7.97 (d, J = 2.0Hz, 1H), 7.72 (dd, J = 10.8, 4.5Hz, 4H), 7.67 (d, J = 7.1Hz, 2H), 7.55 (dd, J = 17.2, 7.8Hz, 2H), 7.47–7.39 (m, 6H), 7.32 (t, J = 7.4Hz, 1H), 7.06 (d, J = 8.6Hz, 1H). Mass spectrometry molecular ion peak: 466.5120; theoretical molecular weight: 467.1456. Elemental analysis theoretical value: C 31 H 21 N3S: C, 79.63; H, 4.53; N, 8.99; Actual elemental analysis values: C, 80.11; H, 4.79; N, 8.77.

[0135] Example 4

[0136] The synthetic route for the synthesis of DA-type organic fluorescent small molecules based on 2-(2-aminophenyl)benzothiazole is as follows:

[0137]

[0138] Under argon protection, 2-(benzothiazol-2-yl)-4-bromoaniline (184 mg, 0.6 mmol), 4-(9-carbazolyl)phenylboronic acid (208 mg, 0.72 mmol), tetra(triphenylphosphine)palladium (34 mg, 0.03 mmol), toluene (20 mL), potassium carbonate aqueous solution (2 mol / L, 12 mL), and ethanol (6 mL) were added separately to 100 mL double-necked flasks, and the mixture was heated to reflux at 90 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction mixture was extracted with water and dichloromethane. The aqueous phase was discarded, and the organic phase was collected. The organic phase was dried over anhydrous magnesium sulfate, and the organic solvent was removed by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography (dichloromethane-petroleum ether, volume ratio 1:2) to obtain a yellow solid product (189 mg, 67%), which is a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazolium, denoted as BTPCz.

[0139] The BTPCz NMR data prepared in this embodiment are as follows:

[0140] 1¹H NMR (500MHz, DMSO) δ 8.27 (d, J = 7.8Hz, 2H), 8.13 (d, J = 7.8Hz, 1H), 8.07 (d, J = 8.1Hz, 1H), 8.00 (d, J = 2.0Hz, 1H), 7.95 (d, J = 8.4Hz, 2H), 7.75–7.68 (m, 3H), 7.58–7.53 (m, 3H), 7.49–7.43 (m, 5H), 7.31 (ddd, J = 7.9, 4.8, 3.1Hz, 2H), 7.08 (d, J = 8.6Hz, 1H). Mass spectrometry molecular ion peak: 466.4799; theoretical molecular weight: 467.1456.

[0141] Example 5

[0142] Fabrication of BTTPE liquid-phase fluorescence sensor:

[0143] The compound BTTPE obtained in Example 1 was mixed with dichloromethane to prepare a solution with a concentration of 2×10⁻⁶. -6 A mol / L BTTPE dichloromethane solution was prepared, and 3 mL of the solution was placed in a quartz cuvette to obtain a BTTPE liquid-phase fluorescence sensor.

[0144] Example 6

[0145] Fabrication of BTTPE filter paper fluorescence sensor:

[0146] The compound BTTPE obtained in Example 1 was mixed with dichloromethane to prepare a BTTPE solution with a concentration of 0.5 mg / mL.

[0147] Filter paper was immersed in BTTPE solution for 10 seconds, then removed and air-dried to obtain a BTTPE filter paper fluorescence sensor. The amount of fluorescent molecules attached was 10. -5 ~10 -4 mg.

[0148] Example 7

[0149] Fabrication of BTTPA, BT3PCz, and BTPCz liquid phase fluorescence sensors:

[0150] The compounds BTTPA, BT3PCz, and BTPCz obtained in Examples 2, 3, and 4 were respectively mixed with dichloromethane to prepare solutions with a concentration of 2 × 10⁻⁶. -6 3 mL of each of the mol / L BTTPA, BT3PCz, and BTPCz dichloromethane solutions were placed in a quartz cuvette to obtain BTTPA, BT3PCz, and BTPCz liquid-phase fluorescence sensors.

[0151] To avoid directly using phosgene, which is highly volatile and toxic, researchers typically use triphosgene, which is less volatile and less toxic, as a substitute. One equivalent of triphosgene can be converted in situ to three equivalents of phosgene under the catalysis of triethylamine (TEA). Therefore, this invention uses TEA to catalyze the in-situ conversion of triphosgene into phosgene for research. Because sarin nerve gas is extremely toxic and dangerous, its production and use are strictly prohibited. A suitable substitute is usually chosen for general studies of sarin. Diethyl chlorophosphate (DCP) has similar chemical properties to sarin but is less toxic. Therefore, DCP is usually chosen as a simulant for sarin gas research.

[0152] Application Example 1

[0153] BTTPE liquid phase fluorescence sensor for liquid phase detection of phosgene:

[0154] Using triphosgene / TEA as a substitute for phosgene, the detection effect of the BTTPE liquid phase fluorescence sensor prepared in Example 5 on phosgene was verified.

[0155] 1) The absorption and emission spectra of the BTTPE liquid-phase fluorescence sensor prepared in Example 5 were recorded using an ultraviolet absorption spectrometer and a fluorescence emission spectrometer, respectively. The results are as follows: Figure 1 As shown, the curve on the left represents the absorption spectrum, and the curve on the right represents the emission spectrum. Figure 1 The results show that the short-wavelength absorption of the BTTPE liquid fluorescence sensor is mainly located at 295 nm, the long-wavelength absorption is mainly located at 335-395 nm, and the fluorescence emission peak is located at 458 nm.

[0156] 2) TEA (100 μM) / triphosgene (10 μM) was added to the BTTPE liquid-phase fluorescence sensor prepared in Example 5. The color change of the resulting mixture was observed, and its ultraviolet absorption spectrum was measured. A BTTPE liquid-phase fluorescence sensor without added TEA (100 μM) / triphosgene (10 μM) was used as a control. The results are as follows: Figure 2 As shown. From Figure 2 As can be seen, the addition of TEA (100 μM) / triphosgene (10 μM) solution significantly altered the UV absorption peaks of the liquid-phase fluorescence sensor. The absorption peak of BTTPE at 395 nm decreased markedly, while new absorption peaks appeared at 458 nm and 472 nm, and the color changed from transparent to pale yellow. Furthermore, an isoabsorption point was observed at 416 nm, indicating that the reaction between BTTPE and phosgene is a single and efficient conversion.

[0157] 3) TEA (100 μM) / triphosgene (concentration range 0–10 μM) was gradually added to the BTTPE liquid-phase fluorescence sensor prepared in Example 5, and the changes in the fluorescence spectrum were observed. The results are as follows: Figure 3 As shown. Figure 3 In the image, (a) shows the fluorescence emission spectra of the BTTPE liquid-phase fluorescence sensor after adding different concentrations of TEA / triphosgene; (b) is a bar chart showing the fluorescence intensity ratios of the BTTPE liquid-phase fluorescence sensor after adding different concentrations of TEA / triphosgene. It can be seen that the emission peak of the BTTPE liquid-phase fluorescence sensor gradually weakens at 458 nm, while the emission peak at 516 nm significantly strengthens, and the fluorescence color changes from blue to bright green, exhibiting high contrast. Further analysis... 516 / I 458 The correlation with triphosgene concentration showed a good linear relationship in the range of 0.5–1 μM, and the calculated limit of detection (LOD) was 2.14 nM, which is equivalent to the LOD of 6.42 nM for phosgene by the BTTPE liquid phase fluorescence sensor.

[0158] 4) Solutions of different interfering substances (diethyl cyanophosphate (DCNP), acetyl chloride (AC), phosphorus oxychloride (POCl3), thionyl chloride (SOCl2), p-toluenesulfonyl chloride (TsCl), and benzoyl chloride (BzCl)) were added to six portions of the BTTPE liquid-phase fluorescence sensor obtained in Example 5 (each interfering substance concentration was 100 μM). A BTTPE liquid-phase sensor with added TEA (100 μM) / triphosgene (10 μM) was used as a control. The color changes of the resulting mixed solutions under natural light and ultraviolet light were observed, and the changes in absorption and emission spectra were recorded and analyzed. The results are as follows: Figure 4 As shown. Figure 4 In the figure, (a) is the UV absorption spectrum after adding other different interfering substances to the BTTPE liquid fluorescence sensor; (b) is a bar chart of the fluorescence intensity ratios after adding other different interfering substances to the BTTPE liquid fluorescence sensor.

[0159] It can be seen that among all interfering substances, only phosgene causes new absorption peaks at 458 nm and 472 nm in the BTTPE liquid-phase fluorescence sensor, and its color changes from transparent to pale yellow under natural light. Similarly, only phosgene induces a decrease in the original emission peak at 458 nm and a significant enhancement in fluorescence at 516 nm. 516 / I 458 The fluorescence reached its maximum value, and a distinct bright green fluorescence was observed. These results indicate that the BTTPE liquid-phase fluorescence sensor has excellent recognition specificity for phosgene.

[0160] 5) Mix DCNP (100μM) / TEA (100μM) / triphosgene (10μM), AC (100μM) / TEA (100μM) / triphosgene (10μM), POCl3 (100μM) / TEA (100μM) / triphosgene (10μM), SOCl2 (100μM) / TEA (100μM) / triphosgene (10μM), and TsCl (100μM) / TEA (100μM)... Solutions of B2Cl (100 μM) / triphosgene (10 μM) and B2Cl (100 μM) / TEA (100 μM) / triphosgene (10 μM) were added to six portions of the BTTPE liquid-phase fluorescence sensors obtained in Example 5, respectively. A BTTPE liquid-phase fluorescence sensor with added TEA (100 μM) / triphosgene (10 μM) was used as a control. The fluorescence changes of the resulting mixed solutions under ultraviolet light irradiation were observed, and the emission spectrum changes were recorded and analyzed. The results are shown below. Figure 5 As shown.

[0161] Compared to the presence of phosgene alone, the coexisting interfering substances have a greater impact on I. 516 / I 458 The effects of intensity and fluorescence color are imperceptible. These results confirm the excellent anti-interference performance of the BTTPE liquid-phase fluorescence sensor.

[0162] Application Example 2

[0163] BTTPE liquid phase fluorescence sensor for liquid phase detection of DCP:

[0164] Using DCP as a substitute for sarin, the detection effect of the BTTPE liquid phase fluorescence sensor prepared in Example 5 on DCP, a substitute for sarin, was verified.

[0165] 1) DCP (1 mM) was added to the BTTPE liquid chromatograph prepared in Example 5, and the changes in the UV absorption spectrum of the resulting mixture were observed. A BTTPE liquid chromatograph without added DCP (1 mM) was used as a control. The results are as follows: Figure 6 As shown. From Figure 6 As can be seen, after adding DCP (1 mM) solution, the original absorption peak of BTTPE liquid phase fluorescence sensor at 395 nm was significantly weakened, a new absorption peak appeared at 490 nm, and an isoabsorption point appeared at 420 nm. This indicates that BTTPE reacts with DCP to form a new chemical substance.

[0166] 2) DCP (concentration ranging from 0 to 1 mM) was gradually added to the BTTPE liquid-phase fluorescence sensor prepared in Example 5, and the changes in the fluorescence spectrum were observed. The results are as follows: Figure 7 As shown. Figure 7In the figure, (a) shows the fluorescence emission spectra after adding different concentrations of DCP to the BTTPE liquid fluorescence sensor; (b) is a bar chart of the fluorescence intensity ratios of the BTTPE liquid fluorescence sensor after adding different concentrations of DCP.

[0167] like Figure 7 As shown in (a), with the gradual addition of DCP (concentration varying from 0 to 1 mM), the original emission peak at 458 nm of the BTTPE liquid chromatograph was quenched in situ, and a new emission peak appeared at 610 nm. The BTTPE liquid chromatograph exhibited a desirable but rare 152 nm emission redshift and provided a high-contrast fluorescence change (from blue to magenta), meaning that DCP could be visually identified by the naked eye under ultraviolet light. Subsequently, by plotting the DCP concentration as I... 610 / I 458 The sensitivity of the BTTPE liquid phase fluorescence sensor is evaluated using a function. For example... Figure 7 As shown in (b) in the figure, I 610 / I 458 It showed a positive correlation with DCP concentration and exhibited a good linear relationship in the low concentration range of 0.1–0.5 mM. Based on the fitted curve, the calculated LOD was as low as 6.8 μM.

[0168] 3) Solutions of different interfering substances (triethyl phosphate (TEP), dimethyl methyl phosphate (DMMP), diethyl cyanophosphate (DCNP), and methyl parathion (PM)) were added to four portions of the BTTPE liquid-phase fluorescence sensor obtained in Example 5 (each interfering substance had a concentration of 1 mM). A BTTPE liquid-phase fluorescence sensor with added DCP (1 mM) was used as a control. The fluorescence color changes of the resulting mixed solutions under ultraviolet light were observed, and the changes in absorption and emission spectra were recorded and analyzed. The results are as follows: Figure 8 As shown.

[0169] Figure 8 In the figure, (a) shows the UV absorption spectrum of the BTTPE liquid fluorescence sensor after adding different interfering substances; (b) is a bar chart showing the fluorescence intensity ratios of the BTTPE liquid fluorescence sensor after adding different interfering substances. It can be seen that the absorption and fluorescence spectra of the BTTPE liquid fluorescence sensor did not change significantly after adding various interfering substances. Only in the presence of DCP did the BTTPE liquid fluorescence sensor exhibit an absorption peak at 490 nm and a maximum Ig. 610 / I 458 The values ​​and significant magenta fluorescence indicate that the BTTPE liquid-phase fluorescence sensor possesses excellent recognition specificity for DCP.

[0170] 4) TEP (1mM) / DCP (1mM), DMMP (1mM) / DCP (1mM), DCNP (1mM) / DCP (1mM), and PM (1mM) / DCP (1mM) solutions were added to four portions of the BTTPE liquid-phase fluorescence sensor obtained in Example 5, respectively. A BTTPE liquid-phase fluorescence sensor with added DCP (1mM) was used as a control. The fluorescence changes of the resulting mixed solutions under ultraviolet light irradiation were observed, and the emission spectrum changes were recorded and analyzed. Figure 9 As shown, the characteristic magenta fluorescence is almost identical in the presence of various interfering substances as it is in the presence of DCP alone. 610 / I 458 The efficiency remained above 71%. These results confirm that the BTTPE liquid-phase fluorescence sensor exhibits excellent anti-interference performance against DCP.

[0171] Application Example 3

[0172] Gas-phase detection of phosgene using BTTPE filter paper fluorescence sensor:

[0173] Using triphosgene / TEA as a substitute for phosgene, the detection effect of the BTTPE filter paper fluorescence sensor prepared in Example 6 on phosgene vapor was verified.

[0174] 1) In order to accurately measure different concentrations of phosgene vapor and increase its commercial application value, the BTTPE filter paper fluorescence sensor prepared in Example 6 was placed in phosgene vapor of different concentrations. Images of the BTTPE filter paper fluorescence sensor corresponding to different concentrations of phosgene vapor under natural light and 365nm ultraviolet light were acquired using a smartphone to obtain a standard fluorescence card that can be accurately and quickly applied in real time. Then, the RGB values ​​of the standard fluorescence card were output in real time using color analysis software on the mobile phone. A standard curve was obtained by linear fitting with phosgene vapor concentration (5-40ppm) as the abscissa and the blue channel quenching rate (1-B / B0) under natural light and G / B (green channel / blue channel) under 365nm ultraviolet light as the ordinate. Figure 10 (a) shows images of the BTTPE filter paper fluorescence sensor exposed to different concentrations of phosgene vapor under natural light and 365nm ultraviolet light; (b) shows the fitted standard curve; (c) shows images of the BTTPE filter paper fluorescence sensor after exposure to different interfering vapors; (d) shows the selective detection results of the BTTPE filter paper fluorescence sensor combined with RGB analysis for phosgene vapor; (e) shows images of the BTTPE filter paper fluorescence sensor after exposure to various interfering / phosgene mixed vapors; and (f) shows the anti-interference detection results of the BTTPE filter paper fluorescence sensor combined with RGB analysis for phosgene vapor.

[0175] like Figure 10As shown in (a), after exposure to different concentrations of phosgene vapor, the BTTPE filter paper fluorescence sensor gradually changes from white to brownish-yellow under natural light and from blue fluorescence to green fluorescence under 365nm ultraviolet light. The unique color and fluorescence changes of the BTTPE filter paper fluorescence sensor endow it with chromogenic-fluorescence dual-mode sensing of phosgene vapor. The standard fluorescence card prepared from the BTTPE filter paper fluorescence sensor can achieve chromogenic and fluorescence detection of phosgene vapor at low concentrations with good sensitivity. By observing the color of the standard fluorescence card, the concentration range of phosgene under experimental conditions can be directly observed and analyzed with the naked eye, accurately distinguishing the concentration of phosgene vapor. In other words, the standard fluorescence card prepared in this invention can accurately distinguish the concentration of phosgene vapor at low concentrations with the naked eye, even without large-scale fluorescence testing instruments.

[0176] Figure 10 Results (b) show that both 1-B / B0 under natural light and G / B under 365nm ultraviolet light exhibit a good linear relationship with phosgene vapor concentration (5–40 ppm), with calculated LODs of 0.79 ppm and 0.29 ppm, respectively. The LODs obtained from the colorimetric-fluorescence dual-mode sensing are significantly lower than the phosgene concentrations defined in the Matheson Gas Data Sheet as posing health risks (e.g., exposure to 20 ppm of phosgene can cause lung damage within two minutes; exposure to 90 ppm of phosgene can be fatal within 30 minutes), and are superior to related methods. This indicates that combining a smartphone with phosgene vapor concentrations can convert images into RGB values ​​in real time, which can then be substituted into a standard curve to obtain the corresponding phosgene vapor concentration, thus achieving the goal of visual quantitative detection of phosgene. This method does not require expensive instruments, effectively eliminates human visual color perception errors through digital means, and has advantages such as portability, speed, and accuracy.

[0177] 2) The BTTPE filter paper fluorescence sensor prepared in Example 6 was placed in an atmosphere containing different interfering gases (SOCl2; POCl3; B2Cl; AC; TsCl; DCNP; HCl; all at a concentration of 50 ppm). A BTTPE filter paper fluorescence sensor placed in phosgene vapor (50 ppm) was used as a control. Images of the BTTPE filter paper fluorescence sensor corresponding to different interfering gases were acquired using a smartphone under natural light and 365 nm ultraviolet light. The RGB values ​​of the images were output in real time using color analysis software on the smartphone, and a bar chart was plotted. The results are shown below. Figure 10 As shown in (c) and (d) in the diagram. Figure 10As shown in (c), the BTTPE filter paper fluorescence sensor exhibits only slight fluorescence enhancement or quenching responses to interfering vapors other than phosgene vapor. Only phosgene vapor produces significant chromogenic and fluorescence responses to the BTTPE filter paper fluorescence sensor. Furthermore, the BTTPE filter paper fluorescence sensor generates maximum values ​​for 1-B / B0 and G / B after interacting with phosgene vapor, which are significantly higher than those of other interfering vapors. This indicates that the BTTPE filter paper fluorescence sensor prepared in this invention has high selectivity for phosgene vapor.

[0178] 3) The BTTPE filter paper fluorescence sensors prepared in Example 6 were placed in atmospheres containing different interfering gases / phosgene vapors (SOCl2 / phosgene; POCl3 / phosgene; BzCl / phosgene; AC / phosgene; TsCl / phosgene; DCNP / phosgene; HCl / phosgene; each gas concentration was 50 ppm). A BTTPE filter paper fluorescence sensor placed in phosgene vapor (50 ppm) was used as a control. Images of the BTTPE filter paper fluorescence sensors corresponding to different interfering gases / phosgene vapors were acquired using a smartphone under natural light and 365 nm ultraviolet light. The RGB values ​​of the images were output in real time using color analysis software on the smartphone, and a bar chart was plotted. The results are shown below. Figure 10 As shown in (e) and (f)f. From Figure 10 As shown in (e), apart from SOCl2 and POCl3, the coexisting interfering gases have no significant impact on the green fluorescence of the BTTPE filter paper fluorescence sensor. Notably, the BTTPE filter paper fluorescence sensor exhibits a clear chromogenic response, effectively compensating for the insufficient fluorescence response. This indicates that the chromogenic-fluorescence dual-mode sensing ensures the accuracy and reliability of phosgene vapor detection through complementary advantages and synergistic response. Furthermore, it was observed that the 1-B / B0 and G / B ratios are not significantly different when phosgene vapor and interfering gases coexist compared to when only phosgene vapor is present. The prepared BTTPE filter paper fluorescence sensor, combined with chromogenic-fluorescence dual-mode sensing, possesses excellent sensing performance, including high sensitivity, good selectivity, and strong anti-interference capability, making it an ideal choice for phosgene detection.

[0179] Application Example 4

[0180] BTTPE filter paper fluorescence sensor for gas-phase detection of DCP:

[0181] Using DCP as a substitute for sarin, the effectiveness of the BTTPE filter paper fluorescence sensor prepared in Example 6 for real-time on-site detection of DCP vapor was verified.

[0182] 1) In order to accurately measure DCP vapor at different concentrations and increase its commercial application value, the BTTPE filter paper fluorescence sensor prepared in Example 6 was placed in DCP vapor of different concentrations. Images of the BTTPE filter paper fluorescence sensor corresponding to different concentrations of DCP vapor under 365nm ultraviolet light were acquired using a smartphone to obtain a standard fluorescence card that can be accurately and quickly applied in real time. Then, the RGB values ​​of the standard fluorescence card were output in real time using color analysis software on the mobile phone. A linear fit was performed with DCP vapor concentration (16-132ppm) as the abscissa and R / B (red channel / blue channel) and R / G (red channel / green channel) under 365nm ultraviolet light as the ordinate to obtain a standard curve. Figure 11 (a) shows images of the BTTPE filter paper fluorescence sensor exposed to different concentrations of DCP vapor under 365nm ultraviolet light; (b) shows the fitted standard curve; (c) shows images of the BTTPE filter paper fluorescence sensor exposed to different interfering vapors and the results of selective detection of DCP vapor combined with RGB analysis; (d) shows images of the BTTPE filter paper fluorescence sensor exposed to various interfering / DCP mixed vapors and the results of anti-interference detection of DCP vapor combined with RGB analysis.

[0183] like Figure 11 As shown in (a), after exposure to different concentrations of DCP vapor, the BTTPE filter paper fluorescence sensor gradually changes from blue fluorescence to magenta fluorescence under 365nm ultraviolet light. The standard fluorescent card prepared from the BTTPE filter paper fluorescence sensor can achieve fluorescence detection of DCP vapor at low concentrations with good sensitivity. By observing the color of the standard fluorescent card, the concentration range of DCP under experimental conditions can be directly observed and analyzed with the naked eye, accurately distinguishing the concentration of DCP vapor. That is, the standard fluorescent card prepared by this invention can accurately distinguish the concentration of DCP vapor at low concentrations with the naked eye without the need for large-scale fluorescence testing instruments.

[0184] Figure 11 Results (b) show that under 365nm ultraviolet light, both R / B and R / G exhibit a good linear relationship with DCP vapor concentration (16–132 ppm), with calculated LOD values ​​of 0.66 ppm and 0.49 ppm, respectively. This indicates that combining a smartphone with DCP vapor concentration can convert images into RGB values ​​in real time, which can then be substituted into a standard curve to obtain the corresponding DCP vapor concentration, thus achieving the goal of visual quantitative detection of DCP. This method does not require expensive instruments, effectively eliminates human visual color perception errors through digital means, and has advantages such as portability, speed, and accuracy.

[0185] 2) The BTTPE filter paper fluorescence sensors prepared in Example 6 were placed in saturated vapors containing different interfering substances (TEP, DMMP, DCNP, PM), while a BTTPE filter paper fluorescence sensor placed in DCP saturated vapor was used as a control. Images of the BTTPE filter paper fluorescence sensors corresponding to different interfering substances were acquired under 365nm ultraviolet light using a smartphone, and the RGB values ​​of the images were output in real time using color analysis software on the smartphone, and a bar chart was plotted. The results are shown below. Figure 11 As shown in (c). From Figure 11 As shown in (c), the BTTPE filter paper fluorescence sensor exhibits only slight fluorescence enhancement or quenching responses to interfering vapors other than DCP vapor; only DCP vapor elicits a fluorescence response from the BTTPE filter paper fluorescence sensor. Furthermore, the BTTPE filter paper fluorescence sensor produces maximum R / B and R / G values ​​after interacting with DCP vapor, significantly higher than those of other interfering vapors. This indicates that the BTTPE filter paper fluorescence sensor prepared in this invention exhibits high selectivity for DCP vapor.

[0186] 3) The BTTPE filter paper fluorescence sensor prepared in Example 6 was placed in saturated vapors containing different interfering gases / DCP (TEP / DCP, DMMP / DCP, DCNP / DCP, PM / DCP). The concentration of the interfering gas was the saturated vapor concentration of each interfering substance. A BTTPE filter paper fluorescence sensor placed in DCP saturated vapor was used as a control. Images of the BTTPE filter paper fluorescence sensors corresponding to different interfering substances / DCP vapors were acquired under 365nm ultraviolet light using a smartphone. The RGB values ​​of the images were output in real time using color analysis software on the smartphone, and a bar chart was plotted. The results are shown below. Figure 11 As shown in (d). From Figure 11 As shown in (d), the coexisting interfering vapors have only a slight effect on the activation of the magenta fluorescence of the BTTPE filter paper fluorescence sensor. R / B and R / G fluctuate within a narrow range. In summary, the prepared BTTPE filter paper fluorescence sensor has advantages such as visual detection, high sensitivity, good selectivity, and anti-interference, and can meet the requirements of lightweight, portable, inexpensive, and environmentally friendly real-time on-site detection.

[0187] Application Example 5

[0188] BTTPE's integrated testing of phosgene and DCP:

[0189] After adding TEA (100 μM) / triphosgene (10 μM) and DCP (7 mM) to the BTTPE liquid-phase fluorescence sensor prepared in Example 5, the changes in fluorescence spectrum were observed, and the results are as follows. Figure 12 As shown. Figure 12The normalized fluorescence spectrum of BTTPE and the fluorescence spectra after the addition of phosgene and DCP, respectively, are shown in the figures. It can be seen that after the addition of phosgene, the emission peak of the BTTPE liquid-phase fluorescence sensor at 458 nm gradually weakens, while the emission peak at 516 nm significantly strengthens, and the fluorescence color changes from blue to bright green, exhibiting high contrast. After the addition of DCP, the original emission peak at 458 nm of the BTTPE liquid-phase fluorescence sensor is quenched in situ, and a new emission peak appears at 610 nm. The BTTPE liquid-phase fluorescence sensor exhibits a desirable but rare 152 nm redshift in emission and provides a high-contrast fluorescence change (from blue to magenta). This means that simultaneous and distinguishable detection of phosgene and DCP can be achieved using only a single organic fluorescent small molecule, providing a highly promising material for the integrated detection of multiple chemical warfare agents.

[0190] Application Example 6

[0191] BTTPA, BT3PCz, and BTPCz provide integrated testing for phosgene and DCP.

[0192] After adding TEA (100 μM) / triphosgene (10 μM) and DCP (7 mM) to the BTTPA, BT3PCz, and BTPCz liquid-phase fluorescence sensors prepared in Example 7, respectively, the changes in fluorescence spectra were observed, and the results are as follows: Figure 13 , 14 As shown in Figure 15. Figure 13 The figures in the middle are the normalized fluorescence spectra of BTTPA and the fluorescence spectra after the addition of phosgene and DCP, respectively. Figure 14 The images show the normalized fluorescence spectrum of BT3PCz and the fluorescence spectra after the addition of phosgene and DCP, respectively. Figure 15 The images show the normalized BTPCz fluorescence spectrum and the fluorescence spectra after the addition of phosgene and DCP, respectively.

[0193] like Figure 13 As shown, after the addition of phosgene, the intensity of the emission peak of BTTPA originally located at 491 nm decreased, and a new emission appeared at 594 nm. Simultaneously, the fluorescence color changed from cyan to orange, which was observable to the naked eye. After the addition of DCP, BTTPA showed almost complete quenching of the original emission peak at 491 nm. Figure 14 As shown, after the addition of phosgene, the emission peak of BT3PCz at 470 nm decreased, and a new emission peak appeared at 534 nm. Simultaneously, the fluorescence color changed from sky blue to yellow-green, which was observable to the naked eye. After the addition of DCP, the original emission peak of BT3PCz at 470 nm decreased, and a weak new emission peak appeared at 598 nm. The fluorescence color changed from sky blue to deep pink. Figure 15As shown, after the addition of phosgene, the emission peak of BTPCz at 454 nm decreased, and a new emission peak appeared at 512 nm. Simultaneously, the fluorescence color changed from blue to bright green, which was observable to the naked eye. After the addition of DCP, the intensity of the original emission peak of BTPCz at 454 nm decreased, and a new emission peak appeared at 598 nm; the fluorescence color changed from blue to magenta. This demonstrates that BTTPA, BT3PCz, and BTPCz can all achieve efficient and distinguishable fluorescence detection of both phosgene and DCP simultaneously.

[0194] In summary, the DA-type organic fluorescent small molecule provided by this invention can achieve single or integrated fluorescence detection of phosgene, sarin, and / or diethyl chlorophosphate. When the DA-type organic fluorescent small molecule provided by this invention is prepared into a fluorescence sensor, it can simultaneously detect trace amounts of phosgene, sarin, and / or diethyl chlorophosphate in both liquid and gas phases, exhibiting advantages such as high sensitivity, good selectivity, low detection cost, strong anti-interference ability, and visual detection. Furthermore, to overcome the inherent limitations of human visual perception, the RGB values ​​of the fluorescence pattern are output in real time via a smartphone APP, enabling visualized quantitative fluorescence detection of gas-phase phosgene and sarin and / or diethyl chlorophosphate (DCP). In addition, the DA-type organic fluorescent small molecule provided by this invention exhibits distinctly different fluorescence responses to phosgene, sarin, and / or diethyl chlorophosphate, achieving the goal of integrated fluorescence detection of phosgene, sarin, and / or diethyl chlorophosphate (DCP).

[0195] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole, characterized in that, It has the structure shown in any one of Equations II to V: Formula II; Formula III; Formula IV; Formula V.

2. The method for preparing the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole according to claim 1, comprising the following steps: Compounds having the structure shown in Formula A, compound B, catalyst, solvent and basic reagent were mixed and subjected to Suzuki-Miyaura coupling reaction to obtain a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole; Formula A; in Formula A, X is Cl, Br, or I; The compound B has the structure shown in any one of formulas B1 to B4: Formula B1; Formula B2; Formula B3; Formula B4; In formulas B1 to B4, Y is a boric acid group or a borate ester group.

3. A liquid-phase fluorescence sensor, comprising a DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole and an organic solvent, wherein the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is the DA-type organic fluorescent small molecule of claim 1 or the DA-type organic fluorescent small molecule prepared by the preparation method of claim 2.

4. The application of the liquid phase fluorescence sensor of claim 3 in the detection of chemical warfare agents, wherein the chemical warfare agents include asphyxiating agents and / or nerve agents; The asphyxiating agent is phosgene; The nerve agent is sarin and / or diethyl chlorophosphate; Phosgene, sarin, and / or diethyl chlorophosphate are detected in liquid form.

5. A filter paper fluorescence sensor, comprising filter paper and a fluorescent material loaded on the surface of the filter paper, wherein the fluorescent material comprises the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole as described in claim 1 or the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole prepared by the preparation method described in claim 2.

6. The application of the filter paper fluorescence sensor of claim 5 in the detection of chemical warfare agents, wherein the chemical warfare agents include asphyxiating agents and / or nerve agents; The asphyxiating agent is phosgene; The nerve agent is sarin and / or diethyl chlorophosphate; Phosgene, sarin, and / or diethyl chlorophosphate are detected in gaseous form.

7. A standard fluorescent card for detecting chemical warfare agents, prepared from the filter paper fluorescent sensor of claim 5, wherein the chemical warfare agents include asphyxiating agents and / or nerve agents; The asphyxiating agents include phosgene; The nerve agents include sarin and / or diethyl chlorophosphate; Phosgene, sarin, and / or diethyl chlorophosphate are detected in gaseous form.

8. The standard fluorescent card according to claim 7, characterized in that, The method for detecting chemical warfare agents includes the visual quantitative fluorescence detection of chemical warfare agents, specifically, the visual quantitative fluorescence detection of chemical warfare agents is performed by combining the RGB values ​​of the fluorescence image output in real time by a smartphone.

9. The application of DA-type organic fluorescent small molecules based on 2-(2-aminophenyl)benzothiazole in integrated fluorescence detection of multiple chemical warfare agents, wherein the DA-type organic fluorescent small molecule based on 2-(2-aminophenyl)benzothiazole is the DA-type organic fluorescent small molecule of claim 1 or the DA-type organic fluorescent small molecule prepared by the preparation method of claim 2; the multiple chemical warfare agents include asphyxiating agents and nerve agents; The asphyxiating agents include phosgene; The nerve agents include sarin and / or diethyl chlorophosphate.

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