Preparation method and application of zinc acetate-ascorbic acid carbon dots
The synthesis of blue fluorescent carbon dots by hydrothermal method of zinc acetate and ascorbic acid solves the controllability and stability of the existing carbon dot synthesis technology, and uses its fluorescence quenching response to achieve rapid quantitative detection of hypochlorite, improving the sensitivity and simplicity of detection.
Patent Information
- Application Number
- CN202510420219.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-06-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The prior art has problems such as insufficient controllability, low quantum yield, poor stability, harsh reaction conditions, and the use of strong acids or organic solvents that may cause environmental pollution when synthesizing carbon dots. At the same time, the existing hypochlorite detection methods also face challenges such as complex pretreatment of samples, narrow dynamic range and difficulty in real-time monitoring.
Using zinc acetate and ascorbic acid as raw materials, a blue fluorescent carbon dot was synthesized by a one-step hydrothermal method, and the fluorescence quenching response was used for rapid quantitative detection of hypochlorite.
The stability of carbon dots and high quantum yield are achieved, the synthesis process is simplified, the sensitivity to hypochlorite detection is improved, and hypochlorite can be detected quickly and quantitatively.
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Figure CN120209832A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of the synthesis of fluorescent carbon dots, and particularly relates to a preparation method and application of zinc acetate-ascorbic acid carbon dots. Background Art
[0002] Hypochlorite (ClO - ) is widely used in people's daily life due to its strong oxidizing property and bleaching ability. It is usually used as a bleaching agent and drinking water disinfectant for industrial bleaching, sewage treatment, etc., and it is very easy to pollute natural water bodies and endanger human health. It is reported that exposure to ClO - will damage the skin, irritate the respiratory tract, damage the esophagus, etc., and excessive accumulation of ClO - in the body will cause various diseases such as cardiovascular diseases, arthritis and even cancer. At present, the main methods for the detection of ClO - include electrochemical analysis, chromatography and fluorescence method. Among them, fluorescence probes have become effective tools for the rapid detection of hypochlorite due to their outstanding advantages such as simplicity, rapidity, high selectivity, high sensitivity and real-time detection.
[0003] Carbon dots (CDs) are a kind of fluorescent carbon nanomaterials discovered in recent years, and their particle sizes are generally distributed in the range of 1-10 nm. Compared with other fluorescent nanomaterials, carbon dots have the characteristics of simple synthesis method, wide raw material sources, easy surface modification, etc. Currently, the commonly used carbon dot synthesis methods are mainly divided into top-down method and bottom-up method. The top-down method generally uses methods such as arc discharge method, electrochemical oxidation method, chemical exfoliation method, etc. to directly exfoliate materials with carbon fiber structure to obtain carbon dots; the bottom-up method is to use organic compounds such as glucose and citric acid to synthesize carbon dots through ultrasonic treatment, hydrothermal treatment and other methods. Because of its excellent optical properties, good stability, good biocompatibility and low environmental harm, it has potential application value in the fields of environmental monitoring, fluorescence analysis, biological imaging, cancer treatment, etc.
[0004] At present, the reported methods for synthesizing carbon dots still have limitations such as insufficient controllability, low quantum yield, poor stability, harsh reaction conditions, and possible environmental pollution caused by the use of strong acids or organic solvents. The existing methods for detecting hypochlorite also face many challenges such as complex sample pretreatment, narrow dynamic range (requiring dilution or concentration), and difficulty in real-time monitoring.
[0005] Therefore, in order to solve the above technical problems, it is necessary for this application to propose a preparation method and application of zinc acetate-ascorbic acid carbon dots. Summary of the Invention
[0006] The purpose of the present invention is to provide a preparation method of zinc acetate-ascorbic acid carbon dots (CDs) and their application in hypochlorite (ClO -) Applications in detection. Using zinc acetate and ascorbic acid as raw materials, a blue fluorescent carbon dot is synthesized by a one-step hydrothermal method. Based on the fluorescence quenching response, it can be used for the rapid quantitative detection of hypochlorite in solution. The properties of this carbon dot are stable and the synthesis method is simple. It has high sensitivity for the detection of hypochlorite and can be used to detect hypochlorite in natural water bodies.
[0007] To achieve the above object, the present invention adopts the following technical solutions:
[0008] A preparation method of zinc acetate-ascorbic acid carbon dots, the specific steps are as follows:
[0009] S1. Weigh a certain mass of zinc acetate and ascorbic acid, dissolve them in water, and mix the zinc acetate solution and the ascorbic acid solution evenly at room temperature to obtain solution A;
[0010] S2. Transfer the solution A in S1 to a hydrothermal reaction kettle, react at 180 °C to 220 °C for 1 to 4 hours to obtain solution B;
[0011] S3. Filter the solution B in S2 with a 0.45 μm filter membrane and freeze-dry it to finally obtain zinc acetate-ascorbic acid carbon dots.
[0012] Preferably, in step S1, the concentration ratio of the zinc acetate solution to the ascorbic acid solution is 1:1.
[0013] Preferably, in step S2, the reaction time is 2 hours and the reaction temperature is 200 °C.
[0014] The quantum yield of the zinc acetate-ascorbic acid carbon dots constructed by the above method is 10.05%.
[0015] The present invention also provides an application of the zinc acetate-ascorbic acid carbon dots obtained by the above preparation method in the detection of hypochlorite. Dilute the zinc acetate-ascorbic acid carbon dot stock solution with deionized water, add different concentrations of hypochlorite solution and mix evenly, and incubate at room temperature. Under the excitation wavelength of 380 nm, as the concentration of hypochlorite gradually increases, the fluorescence intensity of the zinc acetate-ascorbic acid carbon dots gradually decreases, realizing the quantitative detection of hypochlorite.
[0016] Preferably, mix evenly at room temperature (about 10 seconds), and under the excitation wavelength of 380 nm, rapid fluorescence detection is realized.
[0017] By adopting the above technical solutions: A zinc acetate-ascorbic acid fluorescent carbon dot is successfully constructed for the first time by a hydrothermal synthesis method. Under the excitation wavelength of 380 nm, the product has an emission peak at 490 nm and shows blue fluorescence; using quinine sulfate as a standard reference, its quantum yield is 10.05%; using the CDs solution as a probe molecule, adding ClO -It can induce fluorescence quenching of CDs later, and there is a linear response between the concentration of hypochlorite and the fluorescence intensity of CDs, which can be used for the rapid quantitative detection of hypochlorite.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] 1. The carbon dots prepared by the present invention have good stability. Adding hypochlorite at room temperature can induce their fluorescence quenching, and there is a linear relationship between the concentration of hypochlorite and the fluorescence intensity of CDs. This method can achieve the rapid quantitative detection of hypochlorite.
[0020] 2. Zinc acetate and ascorbic acid of the present invention are cheap and easily available, and the synthesis method of the carbon dots is simple and rapid, which is beneficial to large-scale production and use.
[0021] 3. The method for preparing CDs proposed by the present invention is simple, fast, green and environmentally friendly. The product has stable properties and high sensitivity to the detection of hypochlorite, and is an ideal material for environmental detection. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is the excitation spectrum and emission spectrum diagram of zinc acetate-ascorbic acid carbon dots prepared by the present invention;
[0023] Figure 2 It is the fluorescence spectrum diagram of zinc acetate-ascorbic acid carbon dots synthesized by the present invention at different reaction times;
[0024] Figure 3 It is the fluorescence spectrum diagram of zinc acetate-ascorbic acid carbon dots synthesized by the present invention at different temperatures;
[0025] Figure 4 It is the fluorescence spectrum diagram of zinc acetate-ascorbic acid carbon dots synthesized by the present invention with different ratios of zinc acetate and ascorbic acid;
[0026] Figure 5 It is the fluorescence spectrum diagram of zinc acetate-ascorbic acid carbon dot solution after adding different concentrations of hypochlorite in the present invention;
[0027] Figure 6 It is the linear relationship diagram between the fluorescence intensity and the concentration of hypochlorite in the present invention;
[0028] Figure 7 It is the schematic diagram of the anti-interference ability of zinc acetate-ascorbic acid carbon dots to detect hypochlorite after adding different ions in the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that those skilled in the art can better understand the advantages and features of the present invention, and thus make a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the protection scope of the present invention.
[0030] To improve the luminescence performance of the product, the following steps are included:
[0031] Weigh a certain mass of zinc acetate and ascorbic acid, dissolve them in water to prepare a 0.1 M aqueous solution. Take 1 mL each of the prepared zinc acetate and ascorbic acid solutions, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction. After the reaction is completed, cool it to room temperature, and then filter it with a 0.45 μm filter membrane to obtain the product. Use a fluorescence spectrometer to detect the excitation and emission spectra of the product. Change the reaction time and detect the fluorescence spectrum. As the reaction time prolongs, the fluorescence intensity of the product changes. When the reaction time is 2 hours, the fluorescence intensity of the product is the best. Therefore, 2 hours is selected as the optimal reaction time for preparing zinc acetate-ascorbic acid carbon dots.
[0032] Weigh a certain mass of zinc acetate and ascorbic acid, dissolve them in water to prepare a 0.1 M aqueous solution. Take 1 mL each of the prepared zinc acetate and ascorbic acid solutions, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box for hydrothermal reaction for 2 hours. After the reaction is completed, cool it to room temperature, and then filter it with a 0.45 μm filter membrane to obtain the product. Use a fluorescence spectrometer to detect the emission spectrum of the product. Change the reaction temperature and detect the fluorescence spectrum. As the reaction temperature increases, the fluorescence intensity of the product also changes. When the reaction temperature is 200 °C, the fluorescence intensity of the product is the best. Therefore, 200 °C is selected as the optimal reaction temperature for preparing zinc acetate-ascorbic acid carbon dots.
[0033] Weigh a certain mass of zinc acetate and ascorbic acid, dissolve them in water to prepare a 0.1 M aqueous solution. Take 1 mL each of the prepared zinc acetate and ascorbic acid solutions, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 2 hours. After the reaction is completed, cool it to room temperature, and then filter it with a 0.45 μm filter membrane to obtain the product. Use a fluorescence spectrometer to detect the emission spectrum of the product. Change the concentration ratio of the zinc acetate solution to the ascorbic acid solution and detect the fluorescence spectrum. When the concentration ratio of the zinc acetate solution to the ascorbic acid solution is 1:1, the fluorescence intensity of the product reaches the maximum value. Therefore, the concentration ratio of the zinc acetate solution to the ascorbic acid solution of 1:1 is selected as the optimal reaction concentration for preparing zinc acetate-ascorbic acid carbon dots.
[0034] Detection of Hypochlorite Using Zinc Acetate - Ascorbic Acid Carbon Dots as Fluorescent Probes
[0035] Solutions of hypochlorite at different concentrations were respectively added to the zinc acetate - ascorbic acid carbon dot solution and mixed evenly, and mixed evenly at room temperature (about 10 seconds). Under the excitation wavelength of 380 nm, as the concentration of hypochlorite gradually increased, the fluorescence intensity of zinc acetate - ascorbic acid carbon dots gradually decreased, realizing rapid detection.
[0036] After mixing the zinc acetate - ascorbic acid carbon dot solution with the hypochlorite solution, common inorganic salt ions were added and incubated at room temperature for 5 minutes. Under the excitation wavelength of 380 nm, the fluorescence spectra of the carbon dot - hypochlorite mixed solution without adding inorganic salt ions were compared, indicating that the inorganic salt ions had little effect on the fluorescence intensity of the detection system, with excellent anti - interference ability, proving that this method can be used for the quantitative detection of hypochlorite under conventional conditions.
[0037] (I) Preparation and Optimization of Zinc Acetate - Ascorbic Acid Carbon Dots
[0038] Example 1: Take 1 mL of 0.1 M zinc acetate aqueous solution and ascorbic acid aqueous solution respectively, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating oven at 200 °C for hydrothermal reaction for 2 hours, cool to room temperature and filter with a 0.45 μm filter membrane to obtain zinc acetate - ascorbic acid carbon dots.
[0039] Example 2: Take 1 mL of 0.1 M zinc acetate aqueous solution and ascorbic acid aqueous solution respectively, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating oven at 200 °C for hydrothermal reaction for 1 hour, cool to room temperature and filter with a 0.45 μm filter membrane to obtain zinc acetate - ascorbic acid carbon dots.
[0040] Example 3: Take 1 mL of 0.1 M zinc acetate aqueous solution and ascorbic acid aqueous solution respectively, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating oven at 200 °C for hydrothermal reaction for 1.5 hours, cool to room temperature and filter with a 0.45 μm filter membrane to obtain zinc acetate - ascorbic acid carbon dots.
[0041] Example 4: Take 1 mL of 0.1 M zinc acetate aqueous solution and ascorbic acid aqueous solution respectively, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating oven at 200 °C for hydrothermal reaction for 2.5 hours, cool to room temperature and filter with a 0.45 μm filter membrane to obtain zinc acetate - ascorbic acid carbon dots.
[0042] Example 5: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 3 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0043] Example 6: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 4 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0044] Example 7: The zinc acetate-ascorbic acid carbon dots obtained in Example 1, Example 2, Example 3, Example 4, Example 5, and Example 6, as Figure 2 shown, at an excitation wavelength of 380 nm, by comparing their fluorescence emission intensities, it is determined that when the synthesis reaction time of zinc acetate-ascorbic acid carbon dots is 2 hours, the fluorescence emission intensity of zinc acetate-ascorbic acid carbon dots is the strongest.
[0045] Example 8: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 180 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0046] Example 9: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 190 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0047] Example 10: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 210 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0048] Example 11: Take 1 mL of zinc acetate aqueous solution and ascorbic acid aqueous solution with a concentration of 0.1 M each, mix them evenly at room temperature, transfer the mixed solution to a hydrothermal reaction kettle, place it in a heating box at 220 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0049] Example 12: The zinc acetate-ascorbic acid carbon dots obtained in Example 1, Example 8, Example 9, Example 10, and Example 11, as Figure 3As shown, at an excitation wavelength of 380 nm, by comparing the fluorescence emission intensities, it was determined that when the reaction temperature for synthesizing zinc acetate-ascorbic acid carbon dots was 200 °C, the fluorescence emission intensity of zinc acetate-ascorbic acid carbon dots was the strongest.
[0050] Example XIII: Take 1 mL of an aqueous zinc acetate solution with a concentration of 0.1 M and 1 mL of an aqueous ascorbic acid solution with a concentration of 0.2 M, mix them evenly at room temperature, transfer the mixture to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0051] Example XIV: Take 1 mL of an aqueous zinc acetate solution with a concentration of 0.2 M and 1 mL of an aqueous ascorbic acid solution with a concentration of 0.1 M, mix them evenly at room temperature, transfer the mixture to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0052] Example XV: Take 1 mL of an aqueous zinc acetate solution with a concentration of 0.3 M and 1 mL of an aqueous ascorbic acid solution with a concentration of 0.1 M, mix them evenly at room temperature, transfer the mixture to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0053] Example XVI: Take 1 mL of an aqueous zinc acetate solution with a concentration of 0.4 M and 1 mL of an aqueous ascorbic acid solution with a concentration of 0.1 M, mix them evenly at room temperature, transfer the mixture to a hydrothermal reaction kettle, place it in a heating box at 200 °C for hydrothermal reaction for 2 hours, cool it to room temperature, and filter it with a 0.45 μm filter membrane to obtain zinc acetate-ascorbic acid carbon dots.
[0054] Example XVII: For the zinc acetate-ascorbic acid carbon dots obtained in Example I, Example XIII, Example XIV, Example XV, and Example XVI, as Figure 4 shown, at an excitation wavelength of 380 nm, by comparing the fluorescence emission intensities, it was determined that when the concentration ratio of the aqueous zinc acetate solution to the aqueous ascorbic acid solution was 1:1, the fluorescence emission intensity of zinc acetate-ascorbic acid carbon dots was the strongest.
[0055] (II) Quantitative detection of hypochlorite using zinc acetate-ascorbic acid carbon dots as a fluorescence probe
[0056] Example XVIII: Mix solutions of hypochlorite at different concentrations with a zinc acetate-ascorbic acid carbon dot solution, with the final concentration range being 0 - 50 μM. Mix them evenly at room temperature (about 10 seconds), and then the fluorescence spectrum under the condition of an excitation wavelength of 380 nm can be detected using a fluorescence spectrometer.
[0057] In summary, the present invention uses zinc acetate and ascorbic acid as raw materials to synthesize a blue fluorescent carbon dot through a one-step hydrothermal method. Based on the fluorescence quenching response, it can be used for the rapid quantitative detection of hypochlorite in solution. The carbon dot has stable properties and a simple synthesis method, with high sensitivity for the detection of hypochlorite, and can be used to detect hypochlorite in natural water bodies.
[0058] The descriptions and practices disclosed in the present invention are easy to think about and understand for those of ordinary skill in the art. Without departing from the principle of the present invention, several improvements and refinements can also be made. Therefore, the modifications or improvements made without deviating from the spirit of the present invention should also be regarded as within the protection scope of the present invention.
Claims
1. A method for preparing zinc acetate-ascorbic acid carbon dots, characterized in that: The steps include: S1. Weigh a certain amount of zinc acetate and ascorbic acid, dissolve them in water, and mix the zinc acetate solution and the ascorbic acid solution evenly at room temperature to obtain solution A; S2, transfer solution A in S1 to a hydrothermal reactor, react at 180°C to 220°C for 1 to 4 hours to obtain solution B; S3. Filter the solution B in S2 with a 0.45 μm filter membrane and freeze-dry to finally obtain zinc acetate-ascorbic acid carbon dots.
2. The method for preparing zinc acetate-ascorbic acid carbon dots according to claim 1, characterized in that: In the S1, the concentration ratio of the zinc acetate solution to the ascorbic acid solution is 1:
1.
3. The method for preparing zinc acetate-ascorbic acid carbon dots according to claim 1, characterized in that: In S2, the reaction temperature is 200° C. and the reaction time is 2 hours.
4. An application of zinc acetate-ascorbic acid carbon dots obtained by the preparation method according to any one of claims 1 to 3 in hypochlorite detection, characterized in that: The zinc acetate-ascorbic acid carbon dots stock solution was diluted with deionized water, and hypochlorite solutions of different concentrations were added and mixed evenly, and incubated at room temperature. Under the excitation wavelength conditions, as the concentration of hypochlorite gradually increased, the fluorescence intensity of zinc acetate-ascorbic acid carbon dots gradually weakened, thereby achieving detection.
5. The use according to claim 4, characterized in that: Mix well at room temperature and rapid detection can be achieved under 380nm excitation wavelength.