A method for preparing MnO2 / AuOs composite material and its application in the detection of Pb 2+ Applications on
By preparing MnO2/AuOs composite nanomaterials, and utilizing their peroxidase-like activity and the specific binding of Pb2+ to gold, the problem of time-consuming and laborious lead ion detection in existing methods has been solved, enabling rapid and convenient quantitative detection of lead ions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YANCHENG INST OF TECH
- Filing Date
- 2022-07-29
- Publication Date
- 2026-06-26
Smart Images
Figure CN115372298B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of materials preparation and chemical analysis, specifically to a method for preparing a MnO2 / AuOs composite material and the detection of Pb using MnO2 / AuOs. 2+ The method. Background Technology
[0002] Lead is one of the most widely distributed and most toxic heavy metal pollutants. Once ingested through food, lead can damage the nervous, cardiovascular, digestive, and renal systems. Therefore, monitoring and detecting trace amounts of lead ions is crucial for eliminating potential health risks. Currently used methods for lead ion detection include atomic absorption spectrometry, atomic fluorescence spectrometry, and inductively coupled plasma mass spectrometry. However, existing methods suffer from drawbacks such as being time-consuming, labor-intensive, requiring expensive equipment and specialized personnel. Therefore, developing a simple and rapid method for detecting lead ions is urgently needed. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing MnO2 / AuOs composite nanomaterials and to utilize MnO2 / AuOs for detecting Pb. 2+ The method for preparing this MnO2 / AuOs composite nanomaterial includes four steps: MnO2 nanosheet preparation, Au seed preparation, AuOs preparation, and MnO2 / AuOs composite nanomaterial preparation. One of the functions of adding 2-mercaptoethanol during the MnO2 nanosheet preparation process is to increase the adsorption of the AuOs composite material on the MnO2 nanosheet surface. This MnO2 / AuOs composite nanomaterial exhibits peroxidase-like activity, capable of oxidizing the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2 and acetate-sodium acetate buffer solution, changing it from colorless to blue, with a maximum absorption peak at 652 nm. In the presence of 2-mercaptoethanol, Pb... 2+ It can form alloys with gold in composite materials, enhancing the activity of the composite nanomaterials, manifested as enhanced absorption at 652 nm. This is the second effect of 2-mercaptoethanol. The degree of enhancement of peroxidase-like activity in the composite nanomaterials is related to Pb. 2+ The concentration shows a linear relationship, thus enabling quantitative detection of Pb. 2+ Furthermore, in the presence of 2-mercaptoethanol, Pb 2+ The binding with gold exhibits high specificity; therefore, this detection method possesses excellent selectivity, and the presence of other metal ions does not interfere with Pb. 2+ Therefore, MnO2 / AuO2 composite nanomaterials can be used to detect Pb. 2+ The advantages of this detection method are its speed and short processing time, which is beneficial for Pb. 2+ Rapid detection.
[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:
[0005] A method for preparing MnO2 / AuOs composite nanomaterials.
[0006] The preparation of MnO2 / AuOs involves several steps: MnO2 nanosheet preparation, Au seed preparation, AuOs preparation, and the preparation of MnO2 / AuOs composite nanomaterials. NaOH is added to 10 mL of a 1 mmol / L manganese acetate solution to reach pH 10, and the mixture is stirred continuously for 9 hours. After centrifugation, the precipitate is dispersed in 10 mL of a 2-mercaptoethanol aqueous solution to obtain MnO2 nanosheets. Gold seeds are obtained by reacting tetrachloroauric acid and sodium borohydride. 10 mmol / L K2OsCl6 and 10 mmol / L ascorbic acid are added to the gold seed solution, and the reaction yields AuOs composite nanomaterials. The AuOs composite nanomaterials are then added to the MnO2 nanosheet solution and stirred to obtain the MnO2 / AuOs composite nanomaterials.
[0007] In a preferred embodiment of the present invention,
[0008] The preparation of MnO2 / AuOs involves four steps: preparation of MnO2 nanosheets, preparation of Au seeds, preparation of AuOs, and preparation of MnO2 / AuOs composite nanomaterials.
[0009] In a preferred embodiment of the present invention,
[0010] The concentration of 2-mercaptoethanol aqueous solution is 5-50 mmol / L.
[0011] In a preferred embodiment of the present invention,
[0012] Add 10 mmol / L K₂O₅Cl₆ and 10 mmol / L ascorbic acid to the gold seed solution, wherein the volume ratio of K₂O₅Cl₆ to ascorbic acid in the gold seed solution is 1:10:3.
[0013] In a preferred embodiment of the present invention,
[0014] When AuO2 nanosheets are added to the solution of AuO2 composite nanomaterials, the volume ratio of MnO2 to AuO2 is 1:3 to 1:10.
[0015] In a preferred embodiment of the present invention,
[0016] After adding AuO2 nanosheets to the solution, the stirring time is 10-60 minutes.
[0017] In a preferred embodiment of the present invention,
[0018] When AuO2 nanosheets are added to a solution of AuO2 composite nanomaterials, the solution temperature is maintained at 20-40℃ during stirring.
[0019] A method for detecting Pb using MnO2 / AuOs 2+ The method,
[0020] Step 1: Plot the standard curve
[0021] MnO2 / AuO2 composite nanomaterials, acetate-sodium acetate buffer solution, 3,3′,5,5′-tetramethylbenzidine solution, and H2O2 solution were mixed and incubated for 3-20 minutes. The UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which was I0. Then, different concentrations of Pb were added. 2+ After incubating for 5-10 minutes, the UV-Vis absorbance at 652 nm was measured, which was I. Using Pb... 2+ The concentration was used as the x-axis, and the enhancement factor (I-I0) / I0 at 652nm under different concentrations was used as the y-axis to create a standard curve.
[0022] Step 2: Measure Pb in the liquid sample 2+ concentration
[0023] After mixing MnO2 / AuO2 composite nanomaterials, acetate-sodium acetate buffer solution, 3,3′,5,5′-tetramethylbenzidine solution, and H2O2 solution, and incubating for 3-20 minutes, the UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which showed an I0.05 0未 Then, add the unknown sample, incubate for 5-10 minutes, and measure its UV-Vis absorption at 652 nm, which is I. 未 Calculate the enhancement factor (I) at 652 nm. 未 -I 0未 ) / I 0未 The value of Pb is obtained by using the standard curve. 2+ The concentration.
[0024] In a preferred embodiment of the present invention,
[0025] The MnO2 / AuOs composite material is prepared according to the method of claim 1.
[0026] In a preferred embodiment of the present invention,
[0027] After mixing MnO2 / AuOs composite nanomaterials, acetate-sodium acetate buffer solution, 3,3′,5,5′-tetramethylbenzidine solution and H2O2 solution, the incubation time is 3-20 minutes.
[0028] In a preferred embodiment of the present invention,
[0029] The volume ratio of the MnO2 / AuOs composite material solution, the acetate-sodium acetate buffer solution, the 3,3′,5,5′-tetramethylbenzidine solution, and the H2O2 solution is 100:300:300:300.
[0030] In a preferred embodiment of the present invention,
[0031] The concentration of the acetate-sodium acetate buffer solution is 10-80 mmol / L; the concentration of the 3,3′,5,5′-tetramethylbenzidine solution is 1-10 mmol / L; and the concentration of the H2O2 solution is 0.2-5 mol / L.
[0032] The beneficial effects of this invention are:
[0033] The purpose of this invention is to provide a method for preparing MnO2 / AuOs composite nanomaterials and to utilize MnO2 / AuOs for detecting Pb. 2+ The method for preparing this MnO2 / AuOs composite nanomaterial includes four steps: MnO2 nanosheet preparation, Au seed preparation, AuOs preparation, and MnO2 / AuOs composite nanomaterial preparation. One of the functions of adding 2-mercaptoethanol during the MnO2 nanosheet preparation process is to increase the adsorption of the AuOs composite material on the MnO2 nanosheet surface. This MnO2 / AuOs composite nanomaterial exhibits peroxidase-like activity, capable of oxidizing the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2 and acetate-sodium acetate buffer solution, changing it from colorless to blue, with a maximum absorption peak at 652 nm. In the presence of 2-mercaptoethanol, Pb... 2+ It can form alloys with gold in composite materials, enhancing the activity of the composite nanomaterials, manifested as enhanced absorption at 652 nm. This is the second effect of 2-mercaptoethanol. The degree of enhancement of peroxidase-like activity in the composite nanomaterials is related to Pb. 2+ The concentration shows a linear relationship, thus enabling quantitative detection of Pb. 2+ Furthermore, in the presence of 2-mercaptoethanol, Pb 2+ The binding with gold exhibits high specificity; therefore, this detection method possesses excellent selectivity, and the presence of other metal ions does not interfere with Pb. 2+ Therefore, MnO2 / AuO2 composite nanomaterials can be used to detect Pb. 2+ The advantages of this detection method are its speed and short processing time, which is beneficial for Pb. 2+ Rapid detection. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.
[0035] Figure 1 This is a standard curve obtained in Embodiment 6 of the present invention;
[0036] Figure 2 For the detection of Pb in Example 7 of the present invention 2+ Selective experiments. Detailed Implementation
[0037] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.
[0038] In the description of this invention, it should be noted that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.
[0039] The following describes the preparation method of MnO2 / AuOs composite nanomaterials according to embodiments of the present invention and the detection of Pb using MnO2 / AuOs. 2+ The method will be explained in detail.
[0040] Example 1
[0041] This invention provides a method for preparing MnO2 / AuOs composite nanomaterials, comprising the following steps:
[0042] NaOH was added to 10 mL of 1 mmol / L manganese acetate solution to bring the pH to 10. The mixture was stirred for 9 hours and then centrifuged. The precipitate was dispersed in 10 mL of 40 mmol / L 2-mercaptoethanol aqueous solution to obtain MnO2 nanosheets.
[0043] Gold seeds are obtained by reacting tetrachloroauric acid and sodium borohydride.
[0044] Add 10 mL of 10 mmol / L K₂O₅Cl₆ and 3 mL of 10 mmol / L ascorbic acid to 1 mL of gold seed solution to obtain AuO₅ composite nanomaterials.
[0045] Add 50 mL of AuO2 composite nanomaterial to 10 mL of MnO2 nanosheet solution and stir at 30 °C for 20 minutes to obtain MnO2 / AuO2 composite nanomaterial.
[0046] Example 2: Effect of 2-mercaptoethanol aqueous solution concentration on MnO2 / AuOs composite material
[0047] 2-Mercaptoethanol aqueous solutions were prepared at concentrations of 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mmol / L.
[0048] The above experiments show that the MnO2 / AuOs composite material prepared when the concentration of 2-mercaptoethanol aqueous solution is 40 mmol / L is the most uniform.
[0049] Example 3: Effect of the volume ratio of MnO2 to AuOs on the MnO2 / AuOs composite material when AuOs composite nanomaterials are added to MnO2 nanosheet solution.
[0050] The volume ratios of MnO2 and AuOs are 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, and 1:10, respectively.
[0051] The above experiments show that the MnO2 / AuOs composite material prepared at a volume ratio of 1:5 exhibits the strongest peroxidase-like activity.
[0052] Example 4: Effect of stirring time on MnO2 / AuOs composite material after adding AuOs composite nanomaterials to MnO2 nanosheet solution.
[0053] The mixing times were 10, 20, 30, 40, 50, and 60 minutes respectively.
[0054] The above experiments show that the MnO2 / AuOs composite material prepared with a stirring time of 30 minutes exhibits the strongest peroxidase-like activity.
[0055] Example 5: Effect of stirring temperature on MnO2 / AuOs composite material after adding AuOs composite nanomaterials to MnO2 nanosheet solution.
[0056] The stirring temperatures were 20, 25, 30, 35, and 40℃.
[0057] The above experiments show that the MnO2 / AuOs composite material prepared at a stirring temperature of 30℃ exhibits the strongest peroxidase-like activity.
[0058] Example 6: A method for detecting Pb using MnO2 / AuOs 2+ Method
[0059] Step 1: Plot the standard curve
[0060] The MnO2 / AuOs composite nanomaterials obtained according to the method in Example 1 were mixed with an acetate-sodium acetate buffer solution, a 3,3′,5,5′-tetramethylbenzidine solution, and an H2O2 solution, and incubated for 10 minutes. The UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which showed an I0 value. Then, different concentrations of Pb were added.2+ After incubation for 8 minutes, the UV-Vis absorbance at 652 nm was measured, which was I. Using Pb... 2+ A standard curve was plotted with the concentration of the sample as the x-axis and the enhancement factor (I-I0) / I0 at 652 nm at different concentrations as the y-axis, as shown in the attached figure. Figure 1 .
[0061] As shown in the figure, the detection limit (lowest detectable concentration) is 8 nmol / L, and the detection range is 0-350 nmol / L.
[0062] Step 2: Measure Pb in the liquid sample 2+ concentration
[0063] The MnO2 / AuO3 composite nanomaterials obtained according to the method in Example 1 were mixed with an acetate-sodium acetate buffer solution, a 3,3′,5,5′-tetramethylbenzidine solution, and an H2O2 solution. After incubation for 10 minutes, the UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which showed a value of I. 0未 Then, an unknown sample was added, incubated for 8 minutes, and its UV-Vis absorption at 652 nm was measured, which was I. 未 Calculate the enhancement factor (I) at 652 nm. 未 -I 0未 ) / I 0未 The value of Pb is obtained by using the standard curve. 2+ The concentration.
[0064] Example 7: Detection of Pb using MnO2 / AuOs 2+ Selectivity
[0065] The MnO2 / AuOs composite nanomaterials obtained according to the method in Example 1 were mixed with an acetate-sodium acetate buffer solution, a 3,3′,5,5′-tetramethylbenzidine solution, and an H2O2 solution, and incubated for 10 minutes. The UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which showed an I0 value. Then, different metal ions of the same concentration, including Pb, were added. 2+ Ca 2+ Al 3+ Hg 2+ Zn 2+ Fe 3+ Cd 2+ As 3+ Cu 2+ All samples were incubated for 8 minutes, and their UV-Vis absorption at 652 nm was measured, which was I. 金属离子 The enhancement factor (I) of different metal ions at 652 nm 金属离子 A bar chart of -I0) / I0 versus metal ions is shown in the attached figure. Figure 2 .
[0066] As can be seen from the figure, only Pb 2+ This method can maximize the peroxidase-like activity of the composite nanomaterials, thus enabling the selective detection of Pb. 2+ .
[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing MnO2 / AuOs composite nanomaterials, characterized in that, The preparation of MnO2 / AuOs involves several steps: preparation of MnO2 nanosheets, preparation of Au seeds, preparation of AuOs, and preparation of MnO2 / AuOs composite nanomaterials. NaOH is added to 10 mL of 1 mmol / L manganese acetate solution to reach pH 10, and the mixture is stirred continuously for 9 hours. After centrifugation, the precipitate is dispersed in 10 mL of 2-mercaptoethanol aqueous solution to obtain MnO2 nanosheets. Gold seeds are obtained by reacting tetrachloroauric acid and sodium borohydride. 10 mmol / L K2OsCl6 and 10 mmol / L ascorbic acid are added to the gold seed solution, and the reaction yields AuOs composite nanomaterials. AuOs composite nanomaterials are added to the MnO2 nanosheet solution and stirred to obtain MnO2 / AuOs composite nanomaterials.
2. The method for preparing MnO2 / AuOs composite nanomaterials as described in claim 1, characterized in that, The concentration of 2-mercaptoethanol aqueous solution is 5-50 mmol / L.
3. The method for preparing MnO2 / AuOs composite nanomaterials as described in claim 1, characterized in that, Add 10 mmol / L K2OsCl6 and 10 mmol / L ascorbic acid to the gold seed solution, wherein the volume ratio of K2OsCl6 to ascorbic acid in the gold seed solution is 1:10:
3.
4. The method for preparing MnO2 / AuOs composite nanomaterials as described in claim 1, characterized in that, When AuO2 nanosheets are added to the solution of AuO2 composite nanomaterials, the volume ratio of MnO2 to AuO2 is 1:3 to 1:
10.
5. The method for preparing MnO2 / AuOs composite nanomaterials as described in claim 1, characterized in that, After adding AuO2 composite nanomaterials to the MnO2 nanosheet solution, the stirring time is 10-60 minutes.
6. The method for preparing MnO2 / AuOs composite nanomaterials as described in claim 1, characterized in that, When AuO2 nanosheets were added to the solution, the solution temperature was 20-40℃ during stirring.
7. A method for detecting lead ions in a liquid sample, characterized in that, Step 1: Plotting the Standard Curve MnO2 / AuO2 composite nanomaterials, acetate-sodium acetate buffer solution, 3,3′,5,5′-tetramethylbenzidine solution, and H2O2 solution were mixed and incubated for 3-20 minutes. The UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which was I0. Then, different concentrations of Pb were added. 2+ After incubating for 5-10 minutes, its UV-Vis absorption at 652 nm was measured, which was I; using Pb 2+ A standard curve was plotted with the concentration of the concentration on the x-axis and the enhancement factor (I-I0) / I0 at 652nm at different concentrations on the y-axis. Step 2: Measure Pb in the liquid sample 2+ concentration After mixing MnO2 / AuO2 composite nanomaterials, acetate-sodium acetate buffer solution, 3,3′,5,5′-tetramethylbenzidine solution, and H2O2 solution, and incubating for 3-20 minutes, the UV-Vis absorption at 652 nm was measured using a UV spectrophotometer, which showed an I0.05 0未 Then, add the unknown sample, incubate for 5-10 minutes, and measure its UV-Vis absorption at 652 nm, which is I. 未 ; Calculate the enhancement factor (I) at 652 nm. 未 -I 0未 ) / I 0未 The value of Pb is obtained by using the standard curve. 2+ The concentration; The MnO2 / AuOs composite nanomaterial is prepared according to the method of claim 1.
8. The method for detecting lead ions in a liquid sample as described in claim 7, characterized in that, The volume ratio of the MnO2 / AuOs composite material solution, the acetate-sodium acetate buffer solution, the 3,3′,5,5′-tetramethylbenzidine solution, and the H2O2 solution is 100:300:300:
300.
9. The method for detecting lead ions in a liquid sample as described in claim 7, characterized in that, The concentration of the acetate-sodium acetate buffer solution is 10-80 mmol / L; the concentration of the 3,3′,5,5′-tetramethylbenzidine solution is 1-10 mmol / L; and the concentration of the H2O2 solution is 0.2-5 mol / L.