A method for rapid detection of sulfur ions in two channels

Abstract

The application belongs to the field of sensing detection, and relates to a method for rapidly detecting sulfur ions in a double channel, which uses tin telluride nanometer enzyme as a double channel colorimetric probe, detects sulfur ions through two channels, one channel is a specific brown change caused by the binding energy between tin ions and sulfur ions, and is used for detecting sulfur ions with a concentration of greater than or equal to 100 muM; the other channel is a TMB colorimetric method for detecting sulfur ions with a concentration of less than 100 muM; it is found for the first time that the double channel colorimetric probe tin telluride nanometer enzyme can be used for detecting sulfur ions, has high selectivity for sulfur ions, has super-high sensitivity, and is not easily disturbed by other ions; specific brown changes caused by the binding between tin ions and sulfur ions can realize the visualization of sulfur ions in a solution and the rapid, accurate and wide-range concentration determination of photoelectrochemistry; therefore, the method provides a new idea for a 'one platform and multiple channels' detection method of chemical and biological analysis.

Description

Technical fields:

[0001] This invention belongs to the field of sensing and detection, and relates to a method for rapid detection of sulfide ions through dual channels. The method uses tin telluride nanozymes to detect sulfide ions, and utilizes tin telluride nanozymes as a dual-channel colorimetric probe to detect low-concentration and high-concentration sulfide ions respectively, achieving highly sensitive and specific detection of sulfide ions. Background technology:

[0002] Excessive sulfide concentrations pose a significant threat to human health and the environment. Sulfides are common environmental pollutants, primarily released from industries such as paper, petrochemicals, and leather. Hydrogen sulfide, its molecular component, is a gaseous signaling molecule closely related to human health. Therefore, it is necessary to monitor the sulfide content in different composite matrices. Currently, there are many methods for detecting sulfide ions. For example, Chinese patent application CN201710116877.0 discloses a rapid detection complex of sulfide ions, which is a complex of coumarin derivative and copper ions. When used as a fluorescence sensor for detecting sulfide ions in aqueous solutions, this complex exhibits a significant fluorescence enhancement response, a fast response speed, and enables real-time detection of sulfide ions. It also boasts high detection sensitivity with a detection limit as low as 90 nM. Using a standard curve, it can accurately quantify the concentration of sulfide ions in the sample. Chinese patent CN202010548829.0 discloses a visual and photoelectrochemical detection method for sulfide ion concentration: a sensing material coated with an active film is pretreated by immersing it in a solution containing sulfide ions; subsequently, a visual colorimetric method or a photoelectrochemical method is used to detect the sulfide ion concentration in the solution. 2- The ion concentration; the material of the active thin film is a metal oxide, or a heterojunction formed by the metal oxide and other semiconductor metals.

[0003] Nanozymes are enzyme-like nanomaterials considered promising colorimetric probes due to their low cost, high stability, simple preparation, ease of modification, and flexible composition. However, since typical nanozymes are primarily redox enzymes, such as peroxidases, the colorimetric reaction mainly occurs through a redox mechanism. Because various redox species possess equivalent redox capabilities, selectivity is challenged. By modifying their elemental composition and colorimetric principles to design suitable colorimetric reagents, selectivity and sensitivity can be expected to be improved. Currently, there are no reports on the use of nanozymes for the detection of sulfide ions. Summary of the Invention:

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a dual-channel rapid detection method for sulfur ions. This method uses tin telluride nanozyme as a dual-channel colorimetric probe to detect sulfur ions, and uses the same substance to detect low-concentration sulfur ions and high-concentration sulfur ions respectively through different detection principles.

[0005] To achieve the above objectives, this invention provides a method for rapid detection of sulfide ions using a dual-channel tin telluride nanozyme as a dual-channel colorimetric probe. Sulfide ions are detected through two channels: one channel detects sulfide ions at concentrations ≥100 μM by detecting a specific brown color change caused by the binding energy between tin and sulfide ions; the other channel detects sulfide ions at concentrations <100 μM by the TMB colorimetric method.

[0006] The present invention also provides the application of the tin telluride nanozyme as a dual-channel colorimetric probe in the detection of sulfide ions.

[0007] The detection process in practical applications of this invention involves first preparing a phosphate buffer solution, a tin telluride nanozyme aqueous solution, and a 3,3',5 A mixture of 5'-tetramethylbenzidine (TMB) ethanol solution and hydrogen peroxide aqueous solution turns the solution blue. The test solution is then added and reacted for 10 minutes. The color change is observed. If there is no color change, the test solution contains no sulfide ions. If the blue color lightens, the sulfide ion concentration in the test solution is low. The absorption peak at 652 nm is measured, and the final sulfide ion concentration in the detection system is calculated based on the corresponding standard curve. The concentration of sulfide ions in the test solution is then calculated based on the dilution factor. If the solution color changes from blue to white, the absorption peak at 652 nm is measured again, and the final sulfide ion concentration in the detection system is calculated based on the corresponding standard curve. The concentration of sulfide ions in the test solution is then calculated based on the dilution factor. If the solution color changes from blue to white and then to brown, the sulfide ion concentration in the test solution is high. In this case, a mixture of phosphate buffer solution, tin telluride nanozyme aqueous solution, and the test solution is added, and the absorption peak at 405 nm is measured. The final sulfide ion concentration in the detection system is calculated based on the corresponding standard curve. The concentration of sulfide ions in the test solution is then calculated based on the dilution factor.

[0008] The principle of tin telluride nanozyme detection of sulfide ions described in this invention is as follows: Tin telluride nanozyme acts as a dual-channel colorimetric probe. When detecting high concentrations of sulfide ions, the specific binding of the tin telluride nanozyme to sulfide ions turns the solution brown. When detecting low concentrations of sulfide ions, the TMB colorimetric method is used. The peroxidase-like activity of the tin telluride nanozyme decomposes hydrogen peroxide to generate hydroxyl radicals, which oxidize 3,3',5,5'-tetramethylbenzidine to produce a blue oxidation product. The reducing property of sulfide ions then decolorizes the oxidized TMB. The presence or absence of sulfide ions is determined by whether the blue color fades. This invention utilizes the dual-channel detection of sulfide ions using tin telluride nanozyme, improving sensitivity and achieving highly sensitive and specific detection of sulfide ions. Therefore, the process is simpler, more efficient, and more convenient.

[0009] Compared with existing technologies, this invention discovers a dual-channel colorimetric probe, tin telluride nanozyme, capable of detecting sulfide ions. It exhibits high selectivity and ultra-high sensitivity for sulfide ions, and is not easily affected by interference from other ions. Through the specific browning change caused by the binding between tin and sulfide ions, it enables visualization of sulfide ions in solution and rapid, accurate, and wide-range concentration determination via photoelectrochemical methods. Therefore, this method provides a new approach for "one-platform, multi-channel" detection methods in chemical and biological analysis. Attached image description:

[0010] Figure 1 This is a schematic diagram of the reaction mechanism for detecting sulfur ions using tin telluride nanozymes, which is involved in this invention.

[0011] Figure 2 These are characterization images of the tin telluride nanozyme prepared in Example 1 of the present invention, wherein Figure (A) is a transmission electron microscope image; and Figure (B) is a high-resolution transmission electron microscope image.

[0012] Figure 3 This is a schematic diagram of the detection results of high concentration sulfide ions (≥100μM) by the tin telluride nanozyme of Example 2 of the present invention.

[0013] Figure 4 This is a schematic diagram of the detection results of the tin telluride nanozyme in Example 3 of the present invention for low concentrations of sulfur ions (<100 μM).

[0014] Figure 5 This is a schematic diagram of the ion selectivity experiment results of the tin telluride nanozyme in Example 4 of the present invention when detecting high concentrations of sulfur ions (≥100μM).

[0015] Figure 6 This is a schematic diagram of the ion selectivity experiment results of the tin telluride nanozyme in Example 5 of the present invention when detecting low concentrations of sulfur ions (<100 μM). Detailed implementation method:

[0016] The invention will be further described below with reference to examples and accompanying drawings.

[0017] Example 1:

[0018] This embodiment relates to a method for preparing tin telluride nanozymes, the specific process of which is as follows:

[0019] (1) Weigh 0.56816 g of anhydrous Na2SO4 and add it to 40 mL of ultrapure water to prepare a 0.1 mol / L Na2SO4 solution as an electrolyte solution;

[0020] (2) Weigh 0.04g of tin telluride powder and add it to the solution in step (1);

[0021] (3) Two Pt plates (1.0cm) 2 These serve as the working electrode and auxiliary electrode, respectively.

[0022] (4) Electrochemical stripping was performed for 10 hours using a DC power supply at a constant potential of 15V;

[0023] (5) Then let the obtained electrolyte solution stand for 5 minutes and remove the supernatant; then, centrifuge the remaining electrolyte solution containing the precipitate at 10,000 rpm for 10 minutes to obtain the precipitate, then wash it 3 times with ultrapure water, dry it, and obtain the final product tin telluride nanozyme solid powder, which is then freeze-dried and stored.

[0024] The tin telluride nanozyme was characterized using transmission electron microscopy and high-resolution transmission electron microscopy, respectively. The results are as follows: Figure 2 As shown, from Figure 2 As can be seen from A, the prepared tin telluride nanozyme possesses a nanoribbon structure. From... Figure 2 The crystal structure of the tin telluride nanozyme B showed a lattice spacing of approximately 0.152 nm that was consistent with the (200) diffraction plane of the previously reported tin telluride (JCPDS No. 46-1210).

[0025] Example 2:

[0026] This embodiment relates to an experiment on the detection of high concentrations (≥100 μmol / L) of sulfide ions using tin telluride nanozymes. The specific experimental steps are as follows:

[0027] Weigh 0.001 g of the tin telluride nanozyme powder prepared in Example 1 and add it to 1 mL of ultrapure water to prepare a tin telluride nanozyme solution with a concentration of 1 mg / mL; prepare sulfide ion solutions of different concentrations (1 mmol / L, 2 mmol / L, 3 mmol / L, 5 mmol / L, 6 mmol / L, 8 mmol / L, 9 mmol / L); take a 1.5 mL centrifuge tube and add 800 μL of... A phosphate buffer solution with pH=4 was prepared, followed by 100 μL of tin telluride nanozyme solution, and finally 100 μL of sulfide ion solutions of different concentrations. The final sulfide ion concentrations in the system were measured to be 100 μmol / L, 200 μmol / L, 300 μmol / L, 500 μmol / L, 600 μmol / L, 800 μmol / L, and 900 μmol / L. The color changes of each mixed solution were observed, and the ultraviolet absorbance of each mixed solution at a wavelength of 405 nm was measured. A curve was fitted with the final sulfide ion concentration as the x-axis and absorbance as the y-axis. The results are shown below. Figure 3 As shown.

[0028] Observation of the color shows that the mixed solution changes from colorless to brown. This is due to the specific brown change caused by the combination between tin ions and sulfur ions, and the color changes from light brown to dark brown as the concentration of sulfur ions increases.

[0029] from Figure 3 As can be seen, the absorbance at 405 nm gradually increases with the increase of sulfide ion concentration. The relationship between the final sulfide ion concentration (unit: μmol / L) X and the ultraviolet absorption intensity Y is: Y = 0.0002011X + 0.2158, with a linear correlation coefficient R. 2 =0.9948, indicating a good linear relationship between the final concentration of sulfide ions and the ultraviolet absorption intensity, which can be used as a basis for the quantitative detection of sulfide ions.

[0030] In this embodiment, 100 μL of the sulfide ion solution to be tested is added to the detection system (final volume is 1 mL). The sulfide ion concentration is equivalent to being diluted 10 times. Therefore, when testing a solution of unknown concentration, the final concentration of sulfide ions is obtained from the standard curve, and then the final concentration is multiplied by 10 to obtain the sulfide ion concentration of the solution to be tested.

[0031] Example 3:

[0032] This embodiment relates to the detection experiment of tin telluride nanozyme for low concentrations (<100 μmol / L) of sulfide ions. The detection system consists of phosphate buffer solution, tin telluride nanozyme aqueous solution, hydrogen peroxide aqueous solution, and TMB solution. The specific process is as follows:

[0033] Weigh 0.001g of the tin telluride nanozyme powder prepared in Example 1 and add it to 1mL of ultrapure water to prepare a tin telluride nanozyme solution with a concentration of 1mg / mL. Sulfide ion solutions of different concentrations (3 μmol / L, 4 μmol / L, 5 μmol / L, 8 μmol / L, 9 μmol / L, 10 μmol / L, 20 μmol / L, 50 μmol / L, 60 μmol / L, 70 μmol / L, 100 μmol / L, 300 μmol / L, 400 μmol / L, 500 μmol / L, 700 μmol / L, 800 μmol / L, 900 μmol / L) were prepared. A 100 mmol / L hydrogen peroxide aqueous solution and a 20 mmol / L 3,3',5,5'-tetramethylbenzidine ethanol solution were also prepared. In a 1.5 mL centrifuge tube, 730 μL of pH 4 phosphate buffer solution, 50 μL of tin telluride nanozyme aqueous solution, and 100 μL of 3,3',5'-tetramethylbenzidine ethanol solution were added sequentially. A mixture of 5'-tetramethylbenzidine (TMB) in ethanol, 20 μL of hydrogen peroxide solution, and 100 μL of sulfide ion solutions of varying concentrations was reacted for 10 minutes. The color of each mixed solution initially changed from colorless to blue, then gradually faded or turned white. This is because the peroxidase-like activity of the tin telluride nanozyme decomposes hydrogen peroxide to generate hydroxyl radicals, which oxidize 3',5'-tetramethylbenzidine to produce a blue oxidation product. Upon addition of the sulfide ion solution, the sulfide ions decolorize the oxidized TMB. The intensity of the blue color and whether it turns white indicate the qualitative determination of the sulfide ion concentration. The color change pattern of the solutions with different sulfide ion concentrations in this embodiment is as follows: when the final sulfide ion concentration in the detection system is 300 nmol / L, 400 nmol / L, 500 nmol / L, 800 nmol / L, 900 nmol / L, 1 μmol / L, 2 μmol / L, 5 μmol / L, 6 μmol / L, 7 μmol / L, and 10 μmol / L, the solution color changes to light blue; when the final sulfide ion concentration is 30 μmol / L, 40 μmol / L, 50 μmol / L, 70 μmol / L, 80 μmol / L, and 90 μmol / L, the solution color changes to white.

[0034] The ultraviolet absorbance signal intensity of each mixed solution at a wavelength of 652 nm was detected, and the relationship curve between the ultraviolet absorbance signal intensity and the final concentration of sulfide ions was piecewise fitted based on the color change. The results are as follows: Figure 4 As shown.

[0035] from Figure 4 It can be seen that when the solution color turns light blue, the relationship between the final concentration of sulfide ions (unit: μmol / L) and the ultraviolet absorption intensity is: Y = -0.0316X + 0.4608, with a linear correlation coefficient R. 2=0.9900, and as the concentration of sulfide ions increases, its ultraviolet absorption intensity decreases; when the solution color turns white, the relationship between the final concentration of sulfide ions (unit: μmol / L) and the ultraviolet absorption intensity is: Y = -0.0017X + 0.3055, R 2 =0.9929. As the concentration of sulfide ions increases, the ultraviolet absorption intensity decreases. It can be seen that the final concentration of sulfide ions in the range of 0.3-10μM and 30-90μM shows a good linear relationship with the ultraviolet absorption intensity, which can be used as the basis for the quantitative detection of sulfide ions.

[0036] In this embodiment, 100 μL of the sulfide ion solution to be tested is added to the detection system (final volume is 1 mL). The sulfide ion concentration is equivalent to being diluted 10 times. Therefore, when testing a solution of unknown concentration, the final concentration of sulfide ions is obtained from the standard curve, and then the final concentration is multiplied by 10 to obtain the sulfide ion concentration of the solution to be tested.

[0037] Example 4:

[0038] This embodiment relates to an ion selectivity experiment for detecting high concentrations of sulfide ions using tin telluride nanozymes. The specific experiment is as follows:

[0039] Weigh 0.004 g of the tin telluride nanozyme powder prepared in Example 1 and add it to 1 mL of ultrapure water to prepare 4 mg / mL tin telluride nanomaterials. Prepare 1 mol / L solutions of europium ions, magnesium ions, aluminum ions, copper ions, manganese ions, lead ions, sulfate ions, bicarbonate ions, sulfite ions, acetate ions, nitrate ions, chloride ions, bromide ions, carbonate ions, and sulfide ions using EuCl3, MgCl2·6H2O, Al(NO3)3·9H2O, Cu(NO3)2·3H2O, MnCl2·4H2O, Pb(NO3)2, K2SO4, NaHCO3, Na2SO3, CH3COOK, KNO3, KCl, KBr, Na2CO3, and Na2S·9H2O, respectively. Take a 1.5 mL centrifuge tube, add 800 μL of phosphate buffer solution (pH=4), then add 100 μL of tin telluride nanozyme material, and finally add 100 μL of different ionic solutions. React for 10 minutes, observe the color changes of each mixed solution, and measure the ultraviolet absorbance at a wavelength of 405 nm. The results are as follows: Figure 5 As shown in the figure. Observation of color changes revealed that the mixed solution with added sulfide ion solution turned brown, while the mixed solution with added other anions and cations did not change color.

[0040] from Figure 5 It can be seen that the absorbance of the mixed solution with added sulfide ions is significantly higher than that of other ions, indicating that the tin telluride nanozyme has a high selectivity for sulfide ions and is not affected by other anions and cations.

[0041] Example 5:

[0042] This embodiment relates to an ion selectivity experiment for detecting low concentrations of sulfide ions using tin telluride nanozymes. The specific process is as follows:

[0043] Weigh 0.004 g of the tin telluride nanozyme powder prepared in Example 1 and add it to 1 mL of ultrapure water to prepare a 4 mg / mL tin telluride nanozyme solution. Prepare solutions of europium ions, magnesium ions, aluminum ions, copper ions, manganese ions, lead ions, sulfate ions, bicarbonate ions, sulfite ions, acetate ions, nitrate ions, chloride ions, bromide ions, carbonate ions, and sulfide ions with a concentration of 100 μmol / L using EuCl3, MgCl2·6H2O, Al(NO3)3·9H2O, Cu(NO3)2·3H2O, MnCl2·4H2O, Pb(NO3)2, K2SO4, NaHCO3, Na2SO3, CH3COOK, KNO3, KCl, KBr, Na2CO3, and Na2S·9H2O, respectively. Add 730 μL of phosphate buffer solution (pH=4), 50 μL of tin telluride nanozyme, 100 μL of 3,3',5,5'-tetramethylbenzidine solution, 20 μL of hydrogen peroxide solution, and 100 μL of different ion solutions to 1.5 mL centrifuge tubes in the following order: [List of solutions would be inserted here]. React for 10 minutes. The concentration of each ion in the system is 10 μmol / L. Observe the color changes and measure the UV absorbance of each mixed solution at 652 nm. The results are as follows: [List of results would be inserted here]. Figure 6 As shown.

[0044] Observation of color changes revealed that the mixed solution with added sulfide ion solution changed from blue to light blue, while the mixed solution with added other anions and cations did not change color.

[0045] from Figure 6 It can be seen that the absorbance of the mixed solution with added sulfide ions is significantly lower than that of other ions, indicating that the tin telluride nanozyme has a high selectivity for sulfide ions and is not affected by other anions and cations.

Claims

1. A method for rapid detection of sulfide ions via dual channels, characterized in that, Tin telluride nanozyme was used as a dual-channel colorimetric probe to detect sulfide ions. One channel detects sulfide ions at concentrations ≥100 μM by detecting a specific brown color change caused by the binding energy between tin and sulfide ions. The other channel detects sulfide ions at concentrations <100 μM using the TMB colorimetric method. The specific detection process is as follows: phosphate buffer solution, tin telluride nanozyme aqueous solution, 3,3',5,5'-tetramethylbenzidine ethanol solution, and hydrogen peroxide aqueous solution are mixed. The solution turns blue. The test solution is then added and reacted for 10 minutes. The color change of the solution is observed. If there is no color change, it indicates that there are no sulfide ions in the test solution. If the blue color of the solution lightens, it indicates that the concentration of sulfide ions in the test solution is low. Measure the absorption peak at 652 nm of the solution, calculate the final concentration of sulfide ions in the detection system based on the corresponding standard curve, and then calculate the concentration of sulfide ions in the test solution based on the dilution factor. If the solution color changes from blue to white, measure the absorption peak at 652 nm, calculate the final concentration of sulfide ions in the detection system based on the corresponding standard curve, and then calculate the concentration of sulfide ions in the test solution based on the dilution factor. If the solution color changes from blue to white and then to brown, it indicates that the concentration of sulfide ions in the test solution is high. In this case, the phosphate buffer solution, tin telluride nanozyme aqueous solution and the test solution are mixed, the absorption peak of the solution at 405 nm is measured, the final concentration of sulfide ions in the detection system is calculated according to the corresponding standard curve, and the concentration of sulfide ions in the test solution is calculated according to the dilution factor. The principle of the tin telluride nanozyme for detecting sulfide ions is as follows: Tin telluride nanozyme acts as a dual-channel colorimetric probe. When detecting sulfide ions at a concentration ≥100 μM, the specific binding of the tin telluride nanozyme and sulfide ions turns the solution brown. When detecting sulfide ions at a concentration <100 μM, the TMB colorimetric method is used. The peroxidase-like activity of the tin telluride nanozyme decomposes hydrogen peroxide to generate hydroxyl radicals, which oxidize 3,3',5,5'-tetramethylbenzidine to produce a blue oxidation product. The reducing property of sulfide ions then causes the oxidized TMB to fade. The presence or absence of sulfide ions is determined by whether the blue color fades. The specific process for preparing the tin telluride nanozyme is as follows: (1) Weigh anhydrous Na2SO4 and add it to ultrapure water to prepare Na2SO4 solution as electrolyte solution; (2) Weigh out tin telluride powder and add it to the solution in step (1); (3) The two Pt plates are used as the working electrode and the auxiliary electrode, respectively; (4) Electrochemical stripping is performed using a DC power supply at a constant potential; (5) Then let the obtained electrolyte solution stand and remove the supernatant; Subsequently, the remaining electrolyte solution containing the precipitate was centrifuged to obtain the precipitate, which was then washed with ultrapure water and dried to obtain the final product, tin telluride nanozyme solid powder.

2. The method for rapid detection of sulfide ions via dual channels according to claim 1, characterized in that, The concentration of the tin telluride nanozyme aqueous solution is 1 mg / mL.

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