Method for rapidly detecting hydrogen sulfide in solution

Abstract

The invention discloses a method for rapidly detecting hydrogen sulfide in a solution, which comprises the following steps: firstly, sufficiently reacting a nano AgI dispersion liquid with a solution to be detected under an acidic condition to obtain an iodide ion solution, then introducing a CsPbBr3 quantum dot solution into the iodide ion solution, standing for reaction, and determining the hydrogen sulfide in the solution according to fluorescence color change information of the solution after reaction or a right shift change value of a peak position of a fluorescence emission peak. The visual detection on the hydrogen sulfide content is realized. The CsPbBr3 quantum dot is used as a fluorescent probe and can directly react with iodide ions formed by conversion of hydrogen sulfide, conditions such as introduction of other trigger media and the like are not needed, obvious solution fluorescence emission peak appearance position change and fluorescence color change can be initiated, and efficient visual detection of the hydrogen sulfide content is realized; the method has the advantages of simplicity in operation, high sensitivity, rich color change and the like and is suitable for popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis and detection, and particularly relates to a method for quickly detecting hydrogen sulfide in a solution. Background Art

[0002] Hydrogen sulfide (H2S) is an endogenous signal molecule that plays a key role in the fields of biomedicine and food safety. Changes in its concentration play an indicative role in early diagnosis of diseases and detection of food spoilage. In beer production, hydrogen sulfide is one of the key compounds that affect flavor. An appropriate amount of hydrogen sulfide can give beer a full and round taste and a harmonious aroma, while an excessive amount may lead to a decline in the quality of fermented foods and beverages and produce unpleasant odors, such as yeast odor and rotten egg odor, which not only affects the quality of beer and consumer acceptance, but may also cause food safety problems and economic losses. The hydrogen sulfide content in beer is strictly limited, and the hydrogen sulfide content of high-quality beer is usually controlled at 1-5μg / L to avoid the generation of unpleasant odors. Therefore, the development of a rapid, accurate and sensitive hydrogen sulfide detection method has important practical value and realistic significance for ensuring food safety and improving beer quality.

[0003] At present, many methods for detecting hydrogen sulfide have been developed, such as high performance liquid chromatography, electrochemical method, gas chromatography, methylene blue spectrophotometry, electrochemiluminescence, etc. Most of the above methods rely on large and medium-sized instruments, which are time-consuming, expensive, involve complex sample pretreatment processes and require professional technicians. They cannot meet the requirements of quickly, timely and accurately evaluating the content of hydrogen sulfide in the solution. Therefore, it is urgent to develop a fast, sensitive and accurate method to detect hydrogen sulfide in the solution. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies in the prior art and provide a method for detecting hydrogen sulfide in a solution (such as beer, etc.) using perovskite quantum dots. The method has the advantages of simple operation, high sensitivity, and rich color changes. It can realize rapid, quantitative, and visual identification of hydrogen sulfide in the solution and is suitable for promotion and application.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for rapidly detecting hydrogen sulfide in a solution, firstly using AgI nanoparticles to react with hydrogen sulfide in a test solution to generate free iodine ions, then introducing CsPbBr3 quantum dots as fluorescent signal reporters, and using the change in the fluorescent color of the solution after the reaction or the change in the right shift of the fluorescent emission peak position to achieve visual detection of the hydrogen sulfide content, specifically comprising the following steps:

[0007] An acidic buffer solution and a test solution are added to the nano-AgI dispersion. After sufficient reaction, an iodide ion solution is obtained. Then, a CsPbBr3 quantum dot solution is introduced therein to obtain a fluorescent reaction solution. The solution is allowed to react statically. Visual detection of the hydrogen sulfide content is achieved based on the fluorescent color information of the solution after the reaction or the right shift change value of the fluorescent emission peak position.

[0008] Furthermore, the visualization detection step based on the solution fluorescence color information includes: first, a standard solution with a known hydrogen sulfide content is used to fully react with the nano-AgI dispersion to obtain an iodide ion solution, and then a CsPbBr3 quantum dot solution is introduced therein to obtain a reaction solution, which is allowed to stand for reaction to obtain the fluorescence color change pattern of the solution corresponding to different hydrogen sulfide contents after the standing reaction, and then the above steps are repeated to achieve semi-quantitative detection of the hydrogen sulfide content in the detection solution according to the fluorescence color of the solution to be detected after the standing reaction.

[0009] Furthermore, as the hydrogen sulfide content (iodine ion concentration) increases, the fluorescent color of the resulting solution after standing for the reaction changes from green to orange to red.

[0010] Furthermore, the visualization detection step based on the solution fluorescence color information includes: first, a standard solution with a known hydrogen sulfide content is fully reacted with the nano-AgI dispersion to obtain an iodine ion solution, and then a CsPbBr3 quantum dot solution is introduced therein to obtain a reaction solution, and the solution is allowed to stand for reaction, and the RGB values ​​of the solution pictures corresponding to different hydrogen sulfide contents after the standing reaction are obtained (by taking pictures, etc.), and a stoichiometric relationship between the hydrogen sulfide content and the RGB value is established; and the above steps are repeated to achieve quantitative detection of the hydrogen sulfide content in the detection solution according to the RGB value of the solution picture after the solution to be detected is allowed to stand for reaction.

[0011] Furthermore, the visualization detection step based on the change value of the rightward shift of the peak position of the fluorescence emission peak includes: first, a standard solution with a known hydrogen sulfide content is fully reacted with the nano-AgI dispersion to obtain an iodine ion solution, and then a CsPbBr3 quantum dot solution is introduced therein to obtain a reaction solution, and the solution is allowed to stand for reaction to obtain a stoichiometric relationship between different hydrogen sulfide contents and the corresponding change value of the rightward shift of the peak position of the fluorescence emission peak after the standing reaction, and then the above steps are repeated to achieve quantitative detection of the hydrogen sulfide content in the detection solution according to the change value of the rightward shift of the peak position of the fluorescence emission peak after the detection solution is allowed to stand for reaction.

[0012] Furthermore, the rightward shift change value of the fluorescence emission peak position is obtained in the range of 400 to 700 nm.

[0013] Furthermore, the chemometric relationship is a linear regression equation.

[0014] In the above scheme, the fluorescence color change and the rightward shift change value of the fluorescence emission peak position are observed and tested under ultraviolet light irradiation (320-400nm).

[0015] In the above scheme, the sufficient reaction time is 2 to 5 minutes.

[0016] In the above scheme, the concentration of the nano-AgI dispersion is 0.7-1.0 mg / mL.

[0017] In the above scheme, the amount of nano-AgI introduced is excessive relative to the content of hydrogen sulfide in the test sample.

[0018] In the above scheme, the acidic buffer solution is an acetic acid-sodium acetate buffer solution with a pH of 3.6 to 5.4.

[0019] In the above scheme, the concentration of CsPbBr3 quantum dots in the fluorescent reaction solution is 0.24-0.27 mg / mL.

[0020] Furthermore, the concentration of the CsPbBr3 quantum dot solution is 4.0-4.5 mg / mL.

[0021] Preferably, the volume ratio of the CsPbBr3 quantum dot solution to the iodide ion solution is 1:6-16.

[0022] In the above scheme, the static reaction time is 6 to 10 minutes.

[0023] In the above scheme, the particle size of the CsPbBr3 quantum dots is 5 to 20 nm and is rectangular.

[0024] Preferably, the preparation method of CsPbBr3 quantum dots comprises the following steps:

[0025] (1) Pb salt and Cs salt are mixed, an organic solvent is added, and the mixture is heated and stirred to completely dissolve the solid metal salt, and then 5-bromovaleric acid and oleylamine are injected into the obtained solution, and the mixture is stirred in a water bath to react, thereby obtaining a precursor solution;

[0026] (2) The obtained precursor solution is injected into hot water within 10 seconds, fully reacted, refrigerated, centrifuged, and the bottom phase precipitate is removed to obtain a CsPbBr3 dispersion.

[0027] In the above scheme, the Pb salt can be PbBr2; the Cs salt can be CsBr.

[0028] In the above scheme, the molar ratio of the Pb salt to the Cs salt is 1:1.

[0029] In the above scheme, the molar ratio of the Pb salt, 5-bromovaleric acid and oleylamine is 1:(4-5):(4-5).

[0030] In the above scheme, the temperature used for heating and stirring is 50-80°C and the time is 40-60 minutes.

[0031] In the above scheme, the temperature of the water bath stirring reaction is 50-80°C and the time is 10-30 minutes.

[0032] In the above scheme, in step (2), the temperature of the hot water is 50-80°C.

[0033] In the above scheme, in step (2), the refrigeration temperature is 2 to 8° C. and the time is 2 to 4 hours.

[0034] In the above scheme, the sufficient reaction time is 2 to 5 minutes.

[0035] In the above scheme, the nano-AgI is in the form of irregular ellipsoidal particles with a particle size of 200 to 500 nm.

[0036] Preferably, the method for preparing the AgI nanoparticles comprises the following steps:

[0037] The polyvinyl pyrrolidone is heated and dissolved in an alcohol solvent, iodine salt is added, stirred and dissolved, and then a silver salt solution is injected to perform a gradient heating reaction, and then the solution after the reaction is cooled to room temperature; the supernatant is removed by centrifugation, and the bottom phase red precipitate is taken, and then washed, centrifuged, and dried to obtain AgI nanoparticles which are stored in the dark.

[0038] In the above scheme, the alcohol solvent can be ethylene glycol or the like.

[0039] In the above scheme, the molar ratio of the iodine salt, the silver salt and the polyvinyl pyrrolidone is 1:(1-1.25):(0.003-0.005).

[0040] In the above scheme, the molecular weight of the polyvinyl pyrrolidone is 50,000-60,000.

[0041] In the above scheme, the heating and dissolving temperature is 50 to 80° C. and the time is 20 to 40 minutes.

[0042] In the above scheme, the gradient heating reaction step includes: first keeping the temperature at 50-80° for 20-30 minutes, and then heating to 140-180° for 15-30 minutes.

[0043] In the above scheme, the solution to be detected is a water-based solution with an ethanol concentration of less than 8.7 wt %, and specifically can detect beverages such as beer.

[0044] The principle of the present invention is:

[0045] The present invention utilizes the S between unsaturated alkylamine containing C=C double bond and 5-bromopentanoic acid N 2 reaction to form zwitterionic ligands, and optimize the preparation process. The synthesized CsPbBr3 has excellent water stability and a luminescence efficiency of up to 100%, which can effectively enhance the water dispersibility and surface potential of quantum dots and effectively promote their halogen ion (I - )’s capture and reaction-driving effect enables highly sensitive visual detection of hydrogen sulfide.

[0046] The above-mentioned CsPbBr3 fluorescent quantum dots are used to detect hydrogen sulfide. First, AgI nanoparticles are used to react with hydrogen sulfide in the test solution to produce free iodide ions. Then, CsPbBr3 quantum dots are introduced as fluorescent signal reporters. The change in the fluorescent color of the solution after the reaction or the change in the right shift of the fluorescent emission peak position is used to achieve high-sensitivity and visual detection of the hydrogen sulfide content.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1) The present invention uses CsBr and PbBr as main raw materials, combines ligands such as 5-bromovaleric acid and oleylamine, and optimizes its preparation process. The obtained fluorescent probe CsPbBr3 quantum dots have high chemical stability, high photostability and a fluorescence quantum yield close to 100%, which helps to react stably with iodine ions in the solution, and promotes the efficient and high-accuracy detection of hydrogen sulfide content in complex solutions such as beer; in addition, the obtained CsPbBr3 quantum dots can be stored in a refrigerator at 4°C for 1-2 months, and do not need to be prepared and used immediately, which can effectively simplify application requirements and processes and reduce detection costs;

[0049] 2) The CsPbBr3 quantum dots of the present invention can directly react with free iodine ions without introducing other triggering media and other conditions, causing the fluorescence emission peak position of the solution to shift to the right and change the fluorescence color. In particular, the fluorescence color change information is more obvious and intuitive (the fluorescence intensity change method is usually difficult to directly compare with the naked eye), which is more conducive to the visual detection of hydrogen sulfide;

[0050] 3) The present invention introduces nano-AgI material as an anion exchanger, which has good anti-interference properties. When hydrogen sulfide exists in the environment, iodine ions will be released and trigger a reaction between iodine ions and CsPbBr3 quantum dots to produce fluorescence shift and color change, thereby ensuring high accuracy.

[0051] 4) The detection method of the present invention provides a sensitive fluorescence platform for the determination of hydrogen sulfide in solution, which has high accuracy, high sensitivity, and good linear range. Compared with existing detection methods, it avoids the defects of large equipment and long time consumption, and does not have excessive professional requirements for operators. It provides a new idea for the low-cost and efficient determination of hydrogen sulfide in beer and has great application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the fluorescence spectrum of the CsPbBr3 quantum dots of the present invention, where the abscissa is the wave number and the ordinate is the fluorescence intensity.

[0053] Figure 2 This is a transmission electron microscope picture of the CsPbBr3 quantum dots of the present invention.

[0054] Figure 3 The present invention is a schematic diagram of a process for rapidly detecting hydrogen sulfide.

[0055] Figure 4 The CsPbBr3 quantum dots described in Example 2 of the present invention and the AgI nano-solution (+AgI), AgCl nano-solution (+AgCl), AgI+hydrogen sulfide (+AgI+S 2- ) solution system and AgCl+hydrogen sulfide (+AgCl+S 2- ) Fluorescence spectrum of the system after reaction.

[0056] Figure 5 A is a graph showing the changes in color and fluorescence emission peak position after the CsPbBr3 quantum dots described in Example 3 of the present invention react with gradient concentrations of hydrogen sulfide (iodine ions converted by reaction with AgI NPs); B is a linear fitting result of hydrogen sulfide concentration with the RGB value and the change in fluorescence emission peak position, respectively. DETAILED DESCRIPTION

[0057] The applicant will further explain the present invention in detail below in conjunction with specific embodiments so that those skilled in the art can more clearly understand the present invention. However, the following content should not be construed as limiting the scope of protection of the claims of the present invention.

[0058] The chemical reagents and solvents used in the examples were of analytical grade.

[0059] The fluorescence spectrum measurement conditions are as follows: the emission wavelength is 400-700 nm, the excitation wavelength is 365 nm, and the slit width is 10 nm.

[0060] In the following examples, the method for preparing CsPbBr3 quantum dots comprises the following steps:

[0061] 1) Weigh 0.0734 g PbBr2 (0.2 mmol) and 0.0425 g CsBr (0.2 mmol) and mix them in an epoxies tube, then add 5 mL DMF and stir in a 60 °C water bath for 1 h to completely dissolve the solid metal salt;

[0062] 2) 0.0181 g of 5-bromovaleric acid (1 mmol) and 329 μL of OA solution (1 mmol) were injected into the above solution, and the mixture was stirred in a 60° C. water bath for 20 min to obtain a precursor solution;

[0063] 3) Inject 2 mL of the obtained precursor solution into 25 mL of deionized water at 60°C, react for 2 min, and refrigerate in a 4°C refrigerator for 2 h; centrifuge at 10,000 rpm for 10 min to remove the bottom phase precipitate and collect the upper phase CsPbBr3 dispersion (concentration of 4.3 mg / mL).

[0064] The obtained CsPbBr3 quantum dots (initial peak position is 520nm, fluorescence spectrum is shown in Figure 1 ) were characterized by transmission electron microscopy, and the results showed that the product morphology was uniformly dispersed cubic particles (see Figure 2 ).

[0065] The preparation method of the AgI nanoparticles comprises the following steps:

[0066] 1) Measure 12 mL of ethylene glycol in a round-bottom flask, heat it in a 60°C oil bath for 30 min, then add 54 mg of polyvinyl pyrrolidone (PVP, molecular weight 58000), stir and heat until dissolved, add 45 mg of KI (0.27 mM), continue stirring until completely dissolved, then slowly inject 1 mL of AgNO3 solution (concentration 57 mg / mL, solvent ethylene glycol), heat in a 60°C oil bath for 30 min, then continue heating at 160°C for 20 min, and cool the solution to room temperature;

[0067] (2) The cooled solution was transferred to an EP tube and centrifuged at 13,000 rpm for 5 min. The supernatant was removed and the purple precipitate at the bottom phase was taken. The precipitate was washed with ethanol and water respectively (the volume of the solvent used for each washing of the precipitate was 5 mL). After each washing, the solution was centrifuged at 13,000 rpm for 5 min, the supernatant was discarded, and the precipitate was dried at 60°C for 12 h. The obtained AgI nanoparticles were stored in the dark.

[0068] Example 1

[0069] A method for rapid detection of hydrogen sulfide in beer, the detection principle diagram is shown in Figure 3 , specifically including the following steps:

[0070] 1) First, 100 μL of a standard solution with a known hydrogen sulfide content was mixed evenly with 100 μL of an AgI nanoparticle solution (0.7 mg / mL), 20 μL of an acetic acid-sodium acetate buffer solution (pH 3.6, 1 mmol), and 15 μL of deionized water, and the mixture was allowed to react for 2 min. Then, 15 μL of a CsPbBr3 quantum dot solution was added, and the mixture was allowed to react for 8 min. The fluorescence color information of the solution corresponding to different concentrations (0 to 400 μM) of hydrogen sulfide was obtained under ultraviolet light (365 nm) excitation conditions. The specific change pattern was that as the concentration of hydrogen sulfide in the solution system increased, the fluorescence color of the solution after the reaction was green-orange-red in sequence.

[0071] 2) 100 μL of the beer to be tested was mixed evenly with 100 μL of AgI nanoparticle solution (0.7 mg / mL), 20 μL of acetic acid-sodium acetate buffer solution (pH 3.6, 1 mmol), and 15 μL of deionized water, and allowed to react for 2 minutes. Subsequently, 15 μL of CsPbBr3 quantum dot solution was added and allowed to react for 8 minutes. The fluorescent color of the solution after the reaction was visually observed by the naked eye to achieve visual detection of the hydrogen sulfide content in the beer to be tested.

[0072] Example 2

[0073] A method for quantitatively detecting hydrogen sulfide based on CsPbBr3 quantum dots specifically comprises the following steps:

[0074] A 1 mmol hydrogen sulfide solution was prepared, and different volumes of hydrogen sulfide solution and water were mixed (the total volume of hydrogen sulfide solution and water was 100 μL) to obtain hydrogen sulfide dilutions of different concentrations (40 μM, 80 μM, 120 μM, 160 μM, 200 μM, 240 μM, 280 μM, 320 μM, 360 μM, and 400 μM, respectively); 100 μL AgI nano solution (0.7 mg / mL) and 15 μL buffer solution (acetic acid-sodium acetate buffer solution, pH 3.6, 1 mmol) were added, and the reaction was allowed to stand for 2 minutes, 15 μL CsPbBr3 quantum dot solution was added, and the reaction was continued to stand for 8 minutes. Under ultraviolet light (365 nm) excitation conditions, the fluorescence spectrum in the range of 400-700 nm was detected to obtain the peak position information of the fluorescence emission peak of the CsPbBr3 quantum dots before and after the addition of hydrogen sulfide, and the linear relationship with the hydrogen sulfide concentration was established using the peak position change value.

[0075] Figure 4 The CsPbBr3 quantum dots described in Example 2 of the present invention and the AgI nano-solution (+AgI), AgCl nano-solution (+AgCl), AgI+hydrogen sulfide (+AgCl+S 2- ) solution system and AgCl+hydrogen sulfide (+AgI+S2- ) system after the reaction. The results show that when hydrogen sulfide is not added, the peak position of the CsPbBr3 quantum dot solution is 520nm. Simply adding AgI nano-solution (+AgI) does not cause the peak position of the fluorescence emission peak of CsPbBr3 quantum dots to shift to the right. When hydrogen sulfide reacts with AgI nano-solution to produce free iodine ions (+AgI+S 2- ), will cause the fluorescence emission peak position of CsPbBr3 quantum dots to shift to the right, and the introduction of AgCl or AgCl+S 2- After the system was added, although the peak position shifted to the left, the linear relationship after fitting was poor.

[0076] Example 3

[0077] A method for visually detecting hydrogen sulfide based on CsPbBr3 quantum dots specifically comprises the following steps:

[0078] Different volumes of hydrogen sulfide solution were mixed with water in a 96-well plate to keep the final volume of hydrogen sulfide and water at 100 μL to obtain hydrogen sulfide dilutions of different concentrations (40 μM, 80 μM, 120 μM, 160 μM, 200 μM, 240 μM, 280 μM, 320 μM, 360 μM, and 400 μM, respectively). Subsequently, 100 μL of AgI nanoparticle solution (0.7 mg / mL) and 20 μL of buffer solution (acetic acid-sodium acetate buffer solution, pH 3.6, 1 mmol) were added. After reacting for 2 min, 15 μL of The CsPbBr3 quantum dot solution was fully mixed and reacted at room temperature for 8 minutes. The color change of the solution before and after the reaction was observed with the naked eye under ultraviolet light (365nm) and the corresponding RGB value was extracted. At the same time, the fluorescence spectrum in the range of 400-700nm was detected to obtain the peak position information of the fluorescence emission peak of the CsPbBr3 quantum dots before and after the addition of hydrogen sulfide; and the extracted RGB values ​​and peak position change values ​​were used to establish a linear relationship with the hydrogen sulfide concentration.

[0079] The results show that the CsPbBr3 quantum dot solution is green when no hydrogen sulfide is added. After adding hydrogen sulfide solution of different concentrations, the color of the CsPbBr3 quantum dot solution gradually changes from green to orange to red ( Figure 5 A), visual semi-quantitative detection of sodium sulfide can be achieved based on the rich fluorescent color changes of the solution. The linear fitting results obtained based on the RGB value and the peak position change value and the hydrogen sulfide concentration are shown in Figure 5 B, the linear fitting effect is better.

[0080] Comparative Example

[0081] A method for visually detecting hydrogen sulfide based on CsPbBr3 quantum dots, the method being substantially the same as Example 1, except that in the synthesis step (2), sufficient refrigeration is not performed before centrifugation.

[0082] The stability and luminescence efficiency of the quantum dots obtained by the above method are weaker than those of the CsPbBr3 quantum dots obtained in the example, and the FAE color change reaction phenomenon is weak, and the fluorescence intensity is reduced, which is not conducive to the visual detection of hydrogen sulfide in the solution.

[0083] Example 4

[0084] A method for rapidly detecting hydrogen sulfide in beer, wherein the obtained CsPbBr3 quantum dots are applied to detect hydrogen sulfide in a beer matrix, specifically comprising the following steps:

[0085] The beer stock solution was diluted 10 times with deionized water; the addition ratio of beer and water was changed to form beer matrices of different concentrations to make a final volume of 100 μL, and then 100 μL of AgI nanoparticle solution and 20 μL of buffer solution were added, and the mixture was allowed to react for 2 minutes. Then, 15 μL of CsPbBr3 quantum dot solution was added, mixed, and reacted at room temperature for 8 minutes. Then, under ultraviolet light (365 nm) excitation conditions, the fluorescence spectrum in the range of 400-700 nm was detected, and the wavelengths of the fluorescence emission peaks of the CsPbBr3 quantum dots obtained before and after the introduction of hydrogen sulfide into the beer matrix of different concentrations were respectively measured. The change in the peak wavelength position was substituted into the linear equation obtained in Example 3, and the predicted value of the hydrogen sulfide concentration in the beer matrix by the model was calculated, and its recovery rate was calculated. The results are shown in Tables 1 and 2.

[0086] Table 1 Determination results of hydrogen sulfide in beer matrix based on wavelength shift method

[0087]

[0088] Table 2 Determination results of hydrogen sulfide in beer matrix based on colorimetric difference method

[0089]

[0090]

[0091] The results showed that the recoveries of three different concentrations of hydrogen sulfide in the beer matrix were maintained between 92.5% and 116.4% (as shown in Tables 1 and 2), which can achieve specific identification and quantification of hydrogen sulfide in the beer matrix.

[0092] Traditional fluorescent probes for detecting hydrogen sulfide are generally based on fluorescence quenching, and hydrogen sulfide is quantitatively detected through changes in fluorescence intensity. However, changes in fluorescence intensity are difficult to distinguish with the naked eye and require the support of large instruments. The fluorescence detection system established in this article is based on a dual readout mode of color and wavelength shift, which realizes real-time detection and optimizes the synthesis of CsPbBr3 to achieve higher luminescence efficiency and higher stability.

[0093] The above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, so the obvious changes or modifications derived are still within the protection scope of the invention.

Claims

1. A method for rapidly detecting hydrogen sulfide in a solution, characterized in that: The following steps are involved: An acidic buffer solution and a test solution are added to the nano-AgI dispersion to fully react to obtain an iodine ion solution; then a CsPbBr3 quantum dot solution is introduced therein to obtain a fluorescent mixed solution, which is allowed to react statically, and the visual detection of the hydrogen sulfide content is achieved based on the fluorescent color information of the solution after the reaction or the right shift change value of the fluorescent emission peak position.

2. The method according to claim 1, characterized in that The fluorescence color change and the fluorescence emission peak position rightward shift change value are observed under ultraviolet light irradiation conditions.

3. The method according to claim 1, characterized in that The rightward shift change value of the fluorescence emission peak position is obtained in the range of 400 to 700 nm.

4. The method according to claim 1, characterized in that: The sufficient reaction time is 2 to 5 minutes.

5. The method according to claim 1, characterized in that The pH value of the acidic buffer solution is 3.6-5.

4.

6. The method according to claim 1, characterized in that In the fluorescent reaction solution, the concentration of CsPbBr3 quantum dots is 0.24-0.27 mg / mL.

7. The method according to claim 1, characterized in that The static reaction time is 6 to 10 minutes.

8. The method according to claim 1, characterized in that The particle size of the CsPbBr3 quantum dots is 5 to 20 nm and they are rectangular.

9. The method according to claim 1, characterized in that: The preparation method of the CsPbBr3 quantum dots comprises the following steps: (1) Pb salt and Cs salt are mixed, an organic solvent is added, and the mixture is heated and stirred to completely dissolve the solid metal salt, and then 5-bromovaleric acid and oleylamine are injected into the obtained solution, and the mixture is stirred in a water bath to react, thereby obtaining a precursor solution; (2) injecting the obtained precursor solution into hot water, allowing it to react fully, refrigerating, centrifuging, removing the bottom phase precipitate, and obtaining a CsPbBr3 quantum dot dispersion.

10. The method according to claim 1, characterized in that The particle size of the nano-AgI is 200-500nm.

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