A method for constructing a high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite and its application

Abstract

The present invention provides a high-signal-to-noise ratio fluorescence-activated optical probe for detecting hypochlorite and its use. The probe comprises a CdSe / ZnS alloy quantum dot optical probe functionalized with the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile. The probe is based on the nucleophilicity of hypochlorite and utilizes a D-π-A type recognition ligand functionalized CdSe / ZnS quantum dot system. The C=C residue in the ligand molecule serves as the hypochlorite-specific recognition site, and energy transfer between the ligand and the quantum dot allows for high-signal-to-noise ratio fluorescence-activated sensing of trace amounts of hypochlorite. When detecting hypochlorite, a distinct fluorescence response is observed at 582 nm, with the fluorescence color changing from colorless to yellow-green. The detection sensitivity is high, with a detection limit as low as 1.18 μM. Furthermore, using polyvinyl alcohol gel as the substrate for the probe enables fluorescence detection of solid sodium hypochlorite particles in the environment, with a detection limit as low as 0.035 pg. This optical probe provides an effective technical means for the detection of hypochlorite in liquids and solids.

Description

Technical Field

[0001] The invention belongs to the field of analysis and detection, and relates to a construction method and application of a high signal-to-noise ratio fluorescent lighting optical probe for detecting hypochlorite. Background Art

[0002] As a typical oxidant, hypochlorite is widely used in sterilization, disinfection and bleaching due to its strong oxidizing property. However, it is worth noting that long-term exposure to hypochlorite solutions may lead to a variety of human diseases, including cancer, arthritis and heart problems, and excessive emissions may cause environmental pollution. Calcium hypochlorite and brake fluid can be mixed in a certain proportion to be used as an explosive. In addition, potassium chlorate, which is a non-standard explosive, can be easily prepared by mixing low-root (potassium chloride) and disinfectant (sodium hypochlorite) that can be bought in supermarkets. In addition, the chlorine disinfection process can significantly increase the concentration of residual chlorine in drinking water and the production of disinfection by-products (DBPs), which are neurotoxic, cytotoxic, mutagenic and genotoxic. Therefore, the detection of hypochlorite is very necessary.

[0003] The technologies used for on-site detection of hypochlorite include ion mobility spectrometry, gas chromatography / liquid chromatography-mass spectrometry (GC / LC-MS), Raman spectroscopy, fluorescence spectroscopy, etc. Among them, the fluorescent sensing materials used in fluorescence detection technology have been widely studied due to their simple synthesis, high sensitivity, good selectivity and rapid response.

[0004] Semiconductor quantum dots (QDs) possess excellent optical properties and photostability. Their easily modifiable surface chemistry and tunable energy levels have led to their widespread application in both biology and chemistry. Donor-π-conjugated-acceptor (D-π-A) molecules are ideal functionalized ligands. These organic molecules influence the fluorescence emission of quantum dots through the electron-withdrawing ability of the electron acceptor group (A). The π-conjugated bridge of the ligand specifically reacts with hypochlorite, thereby disrupting energy transfer between the quantum dot and the organic ligand, enabling fluorescence detection with a high signal-to-noise ratio.

[0005] Therefore, based on the nucleophilicity of hypochlorite, the present invention utilizes a CdSe / ZnS quantum dot system functionalized with an organic small molecule D-π-A type recognition ligand. The C=C moiety in the ligand serves as a hypochlorite-specific recognition site. Through energy transfer between the ligand and the quantum dot, the system achieves high signal-to-noise ratio fluorescence sensing for trace amounts of hypochlorite. This reagent can produce a change in fluorescence from colorless to yellow-green for hypochlorite, with a clear color contrast that facilitates identification. Summary of the Invention

[0006] The present invention aims to provide a method for constructing and using a high-signal-to-noise ratio fluorescence-lighting optical probe for detecting hypochlorite. The probe is a CdSe / ZnS alloy quantum dot optical probe functionalized with the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile. This optical probe can be used for highly sensitive detection of hypochlorite. Upon detection, a distinct fluorescence lightening response is observed in the solution at 582 nm, with the fluorescence color changing from colorless to yellow-green, and a detection limit as low as 1.18 μM. Furthermore, a PVA gel-based sensing material constructed using polyvinyl alcohol gel as the loading substrate for the probe can achieve on-site semi-quantitative analysis of hypochlorite solid particles, with a detection limit as low as 0.035 pg.

[0007] The present invention discloses a method for constructing a high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite. The probe is a CdSe / ZnS alloy quantum dot optical probe functionalized with the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile, and has the chemical structural formula (1):

[0008]

[0009] The method for constructing a high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite is carried out according to the following steps:

[0010] Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0011] a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at a temperature of -5-0°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline;

[0012] B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3;

[0013] C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5;

[0014] d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1;

[0015] E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:3.

[0016] f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2;

[0017] Preparation of oleic acid-capped CdSe / ZnS quantum dots:

[0018] g. Cadmium oxide, oleic acid, and octadecene were mixed in a volume ratio of 2:5:5 and placed in a closed reaction apparatus. The mixture was evacuated to negative pressure with a vacuum pump and stirred at 140° C. until a colorless, transparent solution was obtained. After 10 minutes, high-purity nitrogen was introduced to obtain a cadmium reaction solution.

[0019] h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative pressure, stir at 140° C. until a colorless transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution.

[0020] i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture;

[0021] j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300°C, and the mixture of step i was added. When the solution fluorescent color was green, the reaction was stopped; methanol and n-hexane were added and fully mixed, and the mixture was centrifuged at 6000 rpm for 5 minutes. The supernatant was discarded and repeated 5 times. After washing away the free oleic acid, the oleic acid-terminated CdSe / ZnS quantum dots obtained were dissolved in 25 ml of dichloromethane for standby use;

[0022] Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0023] k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under nitrogen protection and in the dark; after the reaction solution is cooled, add 25 ml of methanol, and centrifuge three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescent light-up optical probe for detecting hypochlorite.

[0024] The use of the high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite obtained by the method in preparing a quantitative determination of a hypochlorite solution is specifically performed in the following steps:

[0025] a. Dissolve the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe in tetrahydrofuran to prepare a probe solution with a concentration of 0.006 mg / mL;

[0026] b. Prepare sodium hypochlorite standard solution with water as solvent, with the concentration range of 1-10mol / L;

[0027] c. The sodium hypochlorite standard solution prepared in step b was added to the probe solution obtained in step a, and after sufficient reaction, the fluorescence spectrum was measured under the condition of an excitation wavelength of 395 nm. The fluorescence color changed from colorless to yellow-green; the fluorescence intensity at the maximum emission wavelength of 395 nm was linearly fitted with the corresponding hypochlorite concentration to obtain a standard curve, and the content of hypochlorite in the sample to be tested was quantitatively analyzed according to the standard curve;

[0028] The use of the high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite obtained by the method in preparing the detection of hypochlorite solid particles is specifically performed in the following steps:

[0029] a. Soak the polyvinyl alcohol gel in a 0.006 mg / mL tetrahydrofuran solution of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe. After 5 minutes, take it out and air it to semi-dry to obtain a polyvinyl alcohol gel-based sensing material loaded with an optical probe.

[0030] b. Spraying sodium hypochlorite solid particles onto the polyvinyl alcohol gel-based sensing material obtained in step a, and observing the change in fluorescence color with the naked eye under an excitation wavelength of 395 nm.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] The present invention provides a high-signal-to-noise ratio fluorescence-lighting optical probe for detecting hypochlorite and its use. The probe is a CdSe / ZnS alloy quantum dot optical probe functionalized with the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile. The probe is characterized by passivation of the surface of the organic paired quantum dots with push-pull electronic properties, quenching their intrinsic fluorescence. Hypochlorous acid specifically oxidizes and breaks the C=C double bond in the ligand molecule, restoring the quantum dot fluorescence and enabling high-signal-to-noise ratio fluorescence-lighting detection of the target. The optical probe has strong specificity and is resistant to photobleaching due to the excellent photostability of the quantum dots. Furthermore, the color development is stable and clear, making it easy to identify with the naked eye, providing a superior technical means for on-site detection of hypochlorite. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the fluorescence emission spectrum of the reagent of the present invention (5 ml 0.006 mg / mL) detecting 0.1 mol / L sodium hypochlorite solution;

[0034] Figure 2The fluorescence emission spectrum of the reagent of the present invention (2 ml 0.006 mg / mL) detecting 100 μL 0.1-1 mol / L concentration gradient sodium hypochlorite solution;

[0035] Figure 3 This is a linear fitting relationship diagram of the hypochlorite concentration and the fluorescence intensity at 582 nm when the reagent of the present invention (2 ml 0.006 mg / mL) detects 100 μL of 0.1-1 mol / L sodium hypochlorite solution;

[0036] Figure 4 The polyvinyl alcohol gel loaded with the reagent of the present invention (0.006 mg / ml) was sprayed with sodium hypochlorite solid particles, and the fluorescence lighting image was recorded using an inverted fluorescence microscope. DETAILED DESCRIPTION

[0037] Example 1

[0038] Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0039] a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at a temperature of -5°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline;

[0040] B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3;

[0041] C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5;

[0042] d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1;

[0043] E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:3.

[0044] f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2;

[0045] Preparation of oleic acid-capped CdSe / ZnS quantum dots:

[0046] g. Cadmium oxide, oleic acid and octadecene were mixed in a volume ratio of 2:5:5 and placed in a closed reaction apparatus. The mixture was evacuated to negative pressure with a vacuum pump, heated at 140° C. with stirring until a colorless transparent solution was obtained. After 10 minutes, high-purity nitrogen was introduced to obtain a cadmium reaction solution.

[0047] h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative pressure, heat at 140° C. and stir until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution.

[0048] i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture;

[0049] j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h, and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300° C., and the mixture in step i was added, and the reaction was stopped when the solution fluorescent color was green; methanol and n-hexane were then added and fully mixed, and the mixture was centrifuged at 6000 rpm for 5 min, and the supernatant was discarded. This was repeated 5 times, and after washing away the free oleic acid, the obtained oleic acid-terminated CdSe / ZnS quantum dots were dissolved in dichloromethane for standby use;

[0050] Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0051] k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under nitrogen protection in the dark; after the reaction solution is cooled, methanol is added, and centrifuged three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescent light-up optical probe for detecting hypochlorite.

[0052] 50 μL of 84 disinfectant was dropped into 2 ml of a 0.006 mg / mL tetrahydrofuran solution of the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe; under a 395 nm ultraviolet lamp, the solution was observed to change from colorless fluorescence to yellow-green fluorescence, indicating the presence of hypochlorite, a non-standard explosive raw material, in the test object, with obvious color recognition and stable color development.

[0053] Example 2

[0054] Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0055] a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at -3°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin-dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline;

[0056] B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3;

[0057] C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5;

[0058] d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1;

[0059] E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:3.

[0060] f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2;

[0061] Preparation of oleic acid-capped CdSe / ZnS quantum dots:

[0062] g. Cadmium oxide, oleic acid and octadecene were mixed in a volume ratio of 2:5:5 and placed in a closed reaction apparatus. The mixture was evacuated to negative pressure with a vacuum pump, heated at 140° C. with stirring until a colorless transparent solution was obtained. After 10 minutes, high-purity nitrogen was introduced to obtain a cadmium reaction solution.

[0063] h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative pressure, heat at 140° C. and stir until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution.

[0064] i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture;

[0065] j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h, and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300° C., and the mixture in step i was added, and the reaction was stopped when the solution fluorescent color was green; methanol and n-hexane were then added and fully mixed, and the mixture was centrifuged at 6000 rpm for 5 min, and the supernatant was discarded. This was repeated 5 times, and after washing away the free oleic acid, the obtained oleic acid-terminated CdSe / ZnS quantum dots were dissolved in dichloromethane for standby use;

[0066] Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0067] k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under nitrogen protection and in the dark; after the reaction solution is cooled, methanol is added, and centrifuged three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescent light-up optical probe for detecting hypochlorite.

[0068] Add 100 μl of 1 mol / L sodium hypochlorite solution to be tested into 5 ml of 0.006 mg / mL organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe tetrahydrofuran solution; under 395 nm ultraviolet light, the solution can be observed to change from colorless fluorescence to yellow-green fluorescence ( Figure 1 ), indicating the presence of hypochlorite in the test object, with obvious color recognition and stable color development.

[0069] Example 3

[0070] Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0071] a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at -1°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline;

[0072] B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3;

[0073] C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5;

[0074] d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1;

[0075] E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:3.

[0076] f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2;

[0077] Preparation of oleic acid-capped CdSe / ZnS quantum dots:

[0078] g. Mix cadmium oxide, oleic acid, and octadecene in a volume ratio of 2:5:5 and place in a closed reaction apparatus. Pump to negative pressure with a vacuum pump, heat and stir at 140° C. until a colorless, transparent solution is obtained. After 10 minutes, high-purity nitrogen is introduced to obtain a cadmium reaction solution.

[0079] h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative, heat at 140° C. with stirring until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution.

[0080] i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture;

[0081] j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h, and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300° C., and the mixture in step i was added, and the reaction was stopped when the solution fluorescent color turned green; methanol and n-hexane were then added and thoroughly mixed, and the mixture was centrifuged at 6000 rpm for 5 min, and the supernatant was discarded. This was repeated 5 times, and after washing away the free oleic acid, the obtained oleic acid-terminated CdSe / ZnS quantum dots were dissolved in dichloromethane for later use;

[0082] Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0083] k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under light-proof and nitrogen protection; after the reaction solution is cooled, methanol is added, and the solution is centrifuged three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescence-illuminated optical probe for detecting hypochlorite.

[0084] The optical probe was prepared into a tetrahydrofuran solution with a concentration of 0.006 mg / mL. 100 μL of sodium hypochlorite solution with concentrations of 1 M, 2 M, 3 M, 4 M, 5 M, 6 M, 7 M, 8 M, 9 M, and 10 M was added to 2 mL of 0.006 mg / mL optical probe solution to obtain mixed solutions with sodium hypochlorite concentrations of 0.05-0.5 mM. Fluorescence emission spectrum scanning was performed using a fluorescence spectrometer. By comparing the spectra before and after the reaction, it can be seen that the fluorescence intensity at 582 nm gradually increased with the increase of sodium hypochlorite concentration ( Figure 2 ); By establishing a linear relationship between the fluorescence intensity at 582 nm and the concentration of the hypochlorite solution, the linear equation y = 306047.4-8053.2x ( Figure 3 ), according to the detection limit calculation equation: detection limit = 3σ / K, where σ is the standard deviation of the fluorescence spectrometer used, the standard deviation of the fluorescence spectrometer used in the present invention is 3, and K is the slope of the fitted linear equation, that is, K = 8053.2. It can be calculated that the fluorescence detection limit of the reagent is 1.18 μM.

[0085] Example 4

[0086] Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0087] a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at 0°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline;

[0088] B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3;

[0089] C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5;

[0090] d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1;

[0091] E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:3.

[0092] f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2;

[0093] Preparation of oleic acid-capped CdSe / ZnS quantum dots:

[0094] g. Mix cadmium oxide, oleic acid, and octadecene in a volume ratio of 2:5:5 and place in a closed reaction apparatus. Pump to negative pressure with a vacuum pump, stir at 140° C. until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a cadmium reaction solution.

[0095] h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative, stir at 140° C. until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution.

[0096] i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture;

[0097] j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h, and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300° C., and the mixture in step i was added, and the reaction was stopped when the solution fluorescent color turned green; methanol and n-hexane were then added and thoroughly mixed, and the mixture was centrifuged at 6000 rpm for 5 min, and the supernatant was discarded. This was repeated 5 times, and after washing away the free oleic acid, the obtained oleic acid-terminated CdSe / ZnS quantum dots were dissolved in dichloromethane for later use;

[0098] Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile:

[0099] k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under nitrogen protection and in the dark; after the reaction solution is cooled, methanol is added, and centrifuged three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescence-illuminated optical probe for detecting hypochlorite.

[0100] The polyvinyl alcohol gel was immersed in 10 mL of 0.006 mg / mL organic small molecule N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe tetrahydrofuran solution. After 5 minutes, the gel was taken out and aired to semi-dry to obtain a gel-based sensing material. The ground sodium hypochlorite solid was sprayed on the gel-based sensing material. Under the condition of an excitation wavelength of 395 nm, the naked eye could observe the yellow-green fluorescent spots on the gel. The sodium hypochlorite solid particles were qualitatively analyzed, as shown in FIG. Figure 4 As shown in FIG, the mass of the particle is obtained by multiplying the particle volume (the default is a sphere) by the density. The results show that the naked eye detection limit of the PVA gel sensing material for hypochlorite is approximately 0.035 pg.

Claims

1. A method for constructing a high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite, characterized in that The probe is a CdSe / ZnS alloy quantum dot optical probe functionalized with the organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile. The chemical structure is:

2. The method for constructing a high signal-to-noise ratio fluorescent light-emitting optical probe for detecting hypochlorite according to claim 1, characterized in that Follow these steps: Preparation of organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile: a. Dissolve N-phenyldiethanolamine in an organic solvent, tetrahydrofuran or dichloromethane, at a molar ratio of 1:1:3, add triethylamine, slowly add acetyl chloride at a temperature of -5-0°C, react for 12 hours, extract, wash with deionized water until neutral, dry over anhydrous magnesium sulfate, filter, and spin dry to obtain intermediate product 1, N,N-diacetyloxyethylaniline; B, phosphorus oxychloride is slowly added dropwise to DMF, after reacting for 2 hours, it is added dropwise to the N of the intermediate product 1 obtained by step a, in N-diacetyloxyethylaniline, temperature 75 ℃ of reactions 12 hours, after the question response solution is cooled to room temperature, dichloromethane is added as an organic solvent, sodium acetate aqueous solution is slowly added at 0 ℃ of temperature, extracted after reacting for 12 hours at room temperature, washed with deionized water until neutral, extracted after anhydrous magnesium sulfate drying, and spin-dried to obtain the 4-aldehyde N of intermediate product 2, N-diacetyloxyethylaniline, wherein, the mol ratio of intermediate product 1 to phosphorus oxychloride and DMF is 1:1:3; C, the intermediate product 2 obtained in step b was dissolved in methanol, sodium carbonate was added, and the reaction was stirred at room temperature for 12 hours, and dichloromethane and deionized water were added after being spin-dried, and extracted. The organic phase was washed until neutral, dried over anhydrous magnesium sulfate, and filtered to obtain a crude product, and then eluted through a column with ethyl acetate and petroleum ether in a volume ratio of 1:4 to obtain 4-aldehyde N-phenyldiethanolamine of the intermediate product 3, wherein the intermediate product 2 and sodium carbonate mol ratio was 1:2.5; d. The intermediate product 3 obtained in step c was dissolved in anhydrous ethanol, 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the mixture was filtered under reduced pressure to obtain the intermediate product 4 pink fluorescent probe molecule N-phenyldiethanolamine 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5H)-ylidene)malononitrile, wherein the molar ratio of the intermediate product 3 to the 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-acyl)acrylonitrile was 1:1; E. The intermediate product 4 obtained in step d was dissolved in dichloromethane, and trityl mercaptoacetic acid, 4-dimethylaminopyridine, and 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were added successively. The reaction was dried over a room temperature for 24 h, and the intermediate product 5N was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:3 through a column to obtain an intermediate product 5N, N-ditrityl mercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2 (5 hydrogen)-ylidene) malononitrile, wherein the intermediate product 5, trityl mercaptoacetic acid, 4-dimethylaminopyridine, and the mol ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide root were 1:3:0.3:

3. f. The intermediate product 5 obtained in step e was dissolved in dichloromethane, trifluoroacetic acid was added under ice bath, the reaction was dried after 5 h, and the mixture was eluted with ethyl acetate and petroleum ether in a volume ratio of 1:2 to obtain the target product N, N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile, wherein the molar ratio of the intermediate product 5 to trifluoroacetic acid was 1:2; Preparation of oleic acid-capped CdSe / ZnS quantum dots: g. Cadmium oxide, oleic acid and octadecene were mixed in a volume ratio of 2:5:5 and placed in a closed reaction apparatus. The mixture was evacuated to negative pressure with a vacuum pump, heated at 140° C. with stirring until a colorless transparent solution was obtained. After 10 minutes, high-purity nitrogen was introduced to obtain a cadmium reaction solution. h. Mix zinc oxide, oleic acid, and octadecene in a volume ratio of 2:1:1 and place in a closed reaction apparatus. Use a vacuum pump to reduce the pressure to negative pressure, heat at 140° C. and stir until a colorless, transparent solution is obtained. After 10 minutes, introduce high-purity nitrogen to obtain a zinc reaction solution. i. Selenium powder and sulfur powder were mixed in a volume ratio of 1:14:10 and placed in a closed reaction apparatus. Nitrogen was introduced for 10 minutes, and trioctylphosphine was added to dissolve the selenium powder and sulfur powder to obtain a mixture; j. Under nitrogen protection, the cadmium reaction solution obtained in step g, the zinc reaction solution obtained in step h, and octadecene were added, and after being placed in a closed container, the temperature was stirred to 300° C., and the mixture of step i was added, and the reaction was stopped when the solution fluorescent color was green; methanol and n-hexane were added and fully mixed, and the mixture was centrifuged at 6000 rpm for 5 min, and the supernatant was discarded. This was repeated 5 times, and after washing away the free oleic acid, the oleic acid-terminated CdSe / ZnS quantum dots obtained were dissolved in dichloromethane for standby use; Preparation of CdSe / ZnS alloy quantum dot optical probes functionalized with organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile: k. Add the N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene)malononitrile obtained in step f to the oleic acid-capped CdSe / ZnS quantum dot solution obtained in step j, and reflux for 12 hours under nitrogen protection and in the dark; after the reaction solution is cooled, methanol is added, and centrifuged three times at 5000 rpm to obtain a high signal-to-noise ratio fluorescence-illuminated optical probe for detecting hypochlorite.

3. Use of the high signal-to-noise ratio fluorescent optical probe for detecting hypochlorite obtained by the method according to claim 1 in preparing a quantitative determination of hypochlorite solution, wherein the specific operation is carried out according to the following steps: a. The obtained organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe was dissolved in tetrahydrofuran to prepare a probe solution with a concentration of 0.006 mg / mL; b. Prepare sodium hypochlorite standard solution with water as solvent, with a concentration range of 1-10mol / L; c. The sodium hypochlorite standard solution prepared in step b was added to the probe solution obtained in step a. After sufficient reaction, the fluorescence spectrum was measured under an excitation wavelength of 395 nm, and the fluorescence color changed from colorless to yellow-green. The fluorescence intensity at the maximum emission wavelength of 395 nm was linearly fitted with the corresponding hypochlorite concentration to obtain a standard curve. According to the standard curve, the content of hypochlorite in the sample to be tested was quantitatively analyzed.

4. Use of the high signal-to-noise ratio fluorescent optical probe for detecting hypochlorite obtained by the method of claim 1 in preparing a probe for detecting hypochlorite solid particles, wherein the specific operation is carried out according to the following steps: a. Soaking the polyvinyl alcohol gel in the obtained organic small molecule N,N-dimercaptoacetyl 2-(3-cyano-4-(4-hydroxystyrene)-5,5-dimethylfuran-2(5-hydrogen)-ylidene) malononitrile functionalized CdSe / ZnS alloy quantum dot optical probe, taking it out after 5 minutes and airing it to semi-dry, thereby obtaining the polyvinyl alcohol gel-based sensing material loaded with the optical probe; b. Spraying sodium hypochlorite solid particles onto the polyvinyl alcohol gel-based sensing material obtained in step a, and observing the change in fluorescence color with the naked eye under an excitation wavelength of 395 nm.

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