Synthesis of a Nanoenzyme Material Ti-TCPP(Zn) and Its Application in Colorimetric / Photoelectrochemical Detection of Glyphosate

Abstract

The present invention belongs to the field of chemical analysis and detection technology, and relates to the synthesis of a nanoenzyme material Ti-TCPP (Zn) and its application in colorimetric / photoelectrochemical detection of glyphosate. Ti3C2MXene and ZnTCPP can be prepared into Ti-TCPP (Zn) material by a simple solvent thermal method. Due to the interaction between Ti3C2MXene and ZnTCPP, the Ti-TCPP (Zn) has enhanced light-responsive oxidase activity. An enzyme-nanozyme cascade system is constructed using Ti-TCPP (Zn) and acid phosphatase ACP, which has a good colorimetric / photoelectrochemical linear range response to organophosphorus pesticides. The material of the present invention is simple and convenient to prepare, and has the advantages of high sensitivity, large linear range, good stability and repeatability for the detection of organophosphorus pesticides.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical analysis and detection, and particularly relates to the synthesis of a nanoenzyme material Ti-TCPP (Zn) and its application in colorimetric / photoelectrochemical detection of glyphosate. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Organophosphorus pesticide residues pose a significant threat to the environment and human health, attracting researchers' attention to pesticide detection. To date, a variety of methods have been explored and applied to the detection of organophosphorus pesticides, which can be mainly divided into two categories: chromatography and enzyme inhibition. Enzyme inhibition methods offer advantages such as simplicity, rapid response, and low cost. Among these, enzyme inhibition methods based on enzyme-nanozyme cascades are gaining increasing attention.

[0004] MXenes are a class of two-dimensional transition metal carbides, nitrides, and carbonitrides that exhibit exceptional hydrophilicity, excellent electrical conductivity, and chemical properties. MXene-based structures possess electrical conductivity, biocompatibility, large surface area, optical / magnetic, and thermal / mechanical properties, making them promising candidates for the design of high-performance MXene-derived nanozymes.

[0005] In recent years, optical / electrochemical pesticide sensors based on enzyme inhibition have attracted widespread attention and exploration by researchers due to their advantages, such as simple signal reading and visual results. However, most sensors rely on a single signal triggered by the target for analysis. In practical applications, it is difficult to eliminate signal noise caused by interfering substances, which can lead to erroneous or inaccurate results. Therefore, dual-modal pesticide sensors with inherent self-calibration and good interference resistance are expected to provide more reliable results. Meanwhile, the industry has yet to find a dual-modal pesticide sensor based on MOF nanoenzyme materials that has excellent detection performance for glyphosate.

[0006] The paper "Ti3C2Tx MXene Modified with ZnTCPP with Bacteria CapturingCapability and Enhanced Visible Light Photocatalytic Antibacterial Activity" discloses that ZnTCPP-modified Ti3C2Tx MXene has the activity of capturing bacteria and enhancing visible light photocatalytic antibacterial activity, but does not involve the application of this composite material in the detection of organophosphorus pesticides. Summary of the Invention

[0007] In order to solve the above problems, the present invention provides a synthesis of a nanoenzyme material (Ti-TCPP(Zn)) and its application in colorimetric / photoelectrochemical detection of glyphosate.

[0008] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0009] The first aspect of the present invention provides a method for synthesizing a nanoenzyme material Ti-TCPP(Zn), comprising:

[0010] TCPP(Zn) and Ti3C2 MXene are used as raw materials, and a solvent thermal reaction is carried out at 150-160°C for 4-6 hours, followed by cooling to room temperature, solid-liquid separation, washing, and drying to obtain the product.

[0011] The second aspect of the present invention provides a nanoenzyme material Ti-TCPP (Zn) prepared by the above method.

[0012] The third aspect of the present invention provides the use of the above-mentioned nanoenzyme material Ti-TCPP (Zn) in the detection of organophosphorus pesticides, wherein the organophosphorus pesticide is glyphosate.

[0013] Among them, the detection method is colorimetric detection or photoelectrochemical detection.

[0014] The specific steps of the colorimetric detection include:

[0015] Incubating acid phosphatase ACP and glyphosate of known concentration for 15 to 18 minutes to obtain a first mixed solution;

[0016] Adding the above-mentioned Ti-TCPP(Zn) and ascorbic acid-2-phosphate AAP to the first mixed solution, mixing evenly, and incubating for 15 to 18 minutes to obtain a second mixed solution;

[0017] Add TMB to the second mixed solution, mix well, and detect the absorbance value after illumination for 15 to 20 minutes to establish a corresponding relationship between the absorbance value and the glyphosate concentration;

[0018] Using glyphosate of unknown concentration to be tested, repeat the above steps, and determine the glyphosate concentration based on the detected absorbance value.

[0019] Preferably, the incubation time is 15 minutes. The Ti-TCPP(Zn) combined with ACP of the present invention exhibits high sensitivity for detecting glyphosate. The absorbance value of the colorimetric system increases with increasing glyphosate concentration.

[0020] The specific steps of the photoelectrochemical detection include:

[0021] Acid phosphatase ACP and glyphosate of known concentration are incubated for 15 to 18 minutes to obtain a mixed solution;

[0022] The nanoenzyme material Ti-TCPP (Zn) and ascorbic acid-2-phosphate AAP are added to the mixture, mixed evenly, and incubated for 15 to 18 minutes. The cathode photocurrent intensity is detected under light, and a corresponding relationship between the cathode photocurrent intensity and the glyphosate concentration is established;

[0023] Using glyphosate of unknown concentration to be tested, repeat the above steps, and determine the glyphosate concentration based on the detection of cathode photocurrent intensity.

[0024] Preferably, the incubation time is 15 minutes. The Ti-TCPP(Zn) combined with ACP of the present invention exhibits high sensitivity for the detection of glyphosate. The cathode photocurrent intensity of the photoelectrochemical system decreases with increasing glyphosate concentration.

[0025] The beneficial effects of the present invention are:

[0026] (1) Compared with the prior art, the present invention has the following significant advantages: the synthesis process of Ti-TCPP(Zn) is simple, takes less time, and the raw materials are cheap and readily available.

[0027] (2) The present invention synthesizes a MOF nanozyme material (Ti-TCPP(Zn)) by a solvothermal method. The MOF nanozyme material retains the lamellar structure of MXene, and ZnTCPP and Ti3C2 MXene are connected via the carboxyl group (-COOH) of ZnTCPP and the hydroxyl group (-OH) on Ti3C2 MXene. Due to the interaction between Ti3C2 MXene and ZnTCPP, the Ti-TCPP(Zn) has enhanced light-responsive oxidase activity. The Ti-TCPP(Zn) of the present invention is combined with acid phosphatase to construct an enzyme-nanozyme cascade system, which can be applied to colorimetric / photoelectrochemical detection of glyphosate and has the advantages of high sensitivity, low detection limit, and low usage.

[0028] (3) The operation method of the present application is simple, low-cost, universal, and easy to scale up for production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 The synthesis diagram of Ti-TCPP(Zn) in Example 1 (1) and the application of the Ti-TCPP(Zn)-acid phosphatase cascade system in colorimetric / photoelectrochemical detection of glyphosate (2) are shown;

[0031] Figure 2 The SEM images of Ti-TCPP(Zn) in Example 1 (1) and Ti3C2T x , UV-visible absorption spectra of ZnTCPP and Ti-TCPP(Zn) (2);

[0032] Figure 3 Detection graph of glyphosate by Ti-TCPP(Zn) prepared in Example 1, including (A) a linear relationship graph between absorbance value and glyphosate concentration; and (B) a linear relationship graph between cathode photocurrent intensity and glyphosate concentration. DETAILED DESCRIPTION

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] A method for synthesizing a nanoenzyme material Ti-TCPP(Zn), comprising:

[0035] TCPP(Zn) and Ti3C2 MXene are used as raw materials, and a solvent thermal reaction is carried out at 150-160°C for 4-6 hours, followed by cooling to room temperature, solid-liquid separation, washing, and drying to obtain the product.

[0036] More specifically, Ti3C2 MXene and ZnTCPP were dissolved in N,N-dimethylformamide (DMF) at room temperature, and the reaction mixture was stirred at 150 °C for 4 hours. The reaction was cooled to room temperature, centrifuged, and the upper mother liquor was poured out. The product was washed with DMF and methanol three times each, and then dried in vacuum at room temperature to obtain Ti-TCPP(Zn).

[0037] In some embodiments, the mass ratio of the Ti3C2 MXene to ZnTCPP is 1:10 to 12, preferably 1:10.

[0038] In some embodiments, the Ti3C2 MXene is a single-layer Ti3C2.

[0039] In some embodiments, the solvent is N,N-dimethylformamide.

[0040] In some embodiments, the solvothermal reaction is carried out in an inert gas atmosphere, and the inert gas is nitrogen.

[0041] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0042] Example 1

[0043] like Figure 1 The preparation and sensing process of Ti-TCPP(Zn) in this embodiment are as follows:

[0044] (1) 2 mg of Ti3C2 MXene was added to 2 mL of DMF solution, and the mixture was sonicated for 1 minute. Then, 2 mL of ZnTCPP (20 mg) in DMF solution was added to the mixture, sonicated for 10 minutes, and then transferred to a 25 mL reaction tube and reacted at 150°C for 4 hours. After cooling to room temperature, the mixture was washed with DMF and methanol, and the precipitate was collected after centrifugation for 10 minutes. Finally, it was dried in a constant temperature drying oven to obtain Ti-TCPP(Zn) as a brown powder.

[0045] (2) For the colorimetric signal test, 10 μL of glyphosate was first added to a mixture of 10 μL of ACP and 200 μL of NaAc-HAc buffer (0.1 M, pH 4.0) and the mixture was reacted at 37°C for 15 minutes. Then, 10 μL of AAP (15 mM) and 10 μL of Ti-TCPP(Zn) (1 mg mL -1 Finally, 10 μL of TMB (20 mM) was added to the above system, and after 15 minutes of light reaction, the color change was observed and the absorbance at 652 nm was measured.

[0046] (3) For the photoelectrochemical test, the above steps were the same as above. The light source was turned on for 3 seconds and turned off for 3 seconds for 40 seconds, and its photocurrent curve was recorded.

[0047] Example 2

[0048] Morphology and structural characterization of Ti-TCPP(Zn) materials

[0049] The Ti-TCPP(Zn) prepared in Example 1 was characterized by scanning electron microscopy. Figure 2 As shown, from Figure 2 In (1), it can be seen that V-TCPP(Fe) is a lamellar structure; the UV-visible absorption spectrum was used to study the Ti3C2T x , ZnTCPP and Ti-TCPP(Zn). Figure 2 As shown in (2), Ti3C2T x There is no obvious UV absorption, the Soret band of ZnTCPP is at 424nm, and the Q band has two strong peaks at 563nm and 606nm. x After the combination, two strong peaks were also found from Ti-TCPP(Zn). The results confirmed the successful preparation of the material Ti-TCPP(Zn).

[0050] Example 3

[0051] Application of Ti-TCPP(Zn) Material in Glyphosate Detection

[0052] (1) Ti-TCPP(Zn) prepared in Example 1 was prepared into 1 mg mL -1 ACP and glyphosate were incubated for 15 minutes, the above-mentioned Ti-TCPP(Zn) and AAP were added, mixed evenly, and incubated for another 15 minutes, TMB was added, mixed evenly, and the absorbance value was measured after 15 minutes of illumination. The test results are as follows Figure 3 As shown in (A), as the concentration of glyphosate in the test solution increases, the ultraviolet absorbance of the solution also increases. It can be seen that the glyphosate concentration and the absorbance value have a good linear relationship, and the linear range is 0.1-1.0 μM.

[0053] (2) The Ti-TCPP(Zn) prepared in Example 1 was prepared into 1 mg mL -1 ACP and glyphosate were incubated for 15 minutes, and the above-mentioned Ti-TCPP(Zn) and AAP were added, mixed evenly, and incubated for a period of time. The cathode photocurrent intensity was measured under light. The test results are as follows: Figure 3 As shown in (B), as the glyphosate concentration in the test solution increases, the cathodic photocurrent of the solution gradually decreases. This shows that the glyphosate concentration and the cathodic photocurrent intensity have a good linear relationship, with a linear range of 0.05-1.0 μM. This shows that the MXene-derived nanoenzyme material Ti-TCPP(Zn) has a wide detection range for glyphosate.

[0054] Example 4

[0055] The preparation of Ti-TCPP(Zn) of the present embodiment is as follows:

[0056] (1) 2 mg of Ti3C2 MXene was added to 2 mL of DMF solution, and the mixture was sonicated for 1 minute. Then, 2.2 mL of ZnTCPP (22 mg) in DMF solution was added to the mixture, sonicated for 10 minutes, and then transferred to a 25 mL reaction tube and reacted at 155 °C for 5 hours. After cooling to room temperature, the mixture was washed with DMF and methanol, and the precipitate was collected after centrifugation for 10 minutes. Finally, it was dried in a constant temperature drying oven to obtain Ti-TCPP(Zn) as a brown powder.

[0057] The test results show that the Ti-TCPP(Zn) prepared in this example can be used for colorimetric / photoelectrochemical detection of glyphosate, and has the advantages of high sensitivity, low detection limit, and low usage.

[0058] Example 5

[0059] The preparation and sensing process of Ti-TCPP(Zn) in this embodiment are as follows:

[0060] (1) 2 mg of Ti3C2 MXene was added to 2 mL of DMF solution, and the mixture was sonicated for 1 minute. Then, 2.4 mL of ZnTCPP (24 mg) in DMF solution was added to the mixture, sonicated for 10 minutes, and then transferred to a 25 mL reaction tube and reacted at 160°C for 6 hours. After cooling to room temperature, the mixture was washed with DMF and methanol, and the precipitate was collected after centrifugation for 10 minutes. Finally, it was dried in a constant temperature drying oven to obtain Ti-TCPP(Zn) as a brown powder.

[0061] The test results show that the Ti-TCPP(Zn) prepared in this example can be used for colorimetric / photoelectrochemical detection of glyphosate, and has the advantages of high sensitivity, low detection limit, and low usage.

[0062] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or to replace portions thereof with equivalents. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for detecting organophosphorus pesticides using nanoenzyme material Ti-ZnTCPP, characterized in that: The detection method is colorimetric detection or photoelectrochemical detection; The synthesis method of the nanoenzyme material Ti-ZnTCPP comprises: ZnTCPP and Ti3C2 MXene are used as raw materials, and solvent thermal reaction is carried out at 150-160°C for 4-6 hours, cooled to room temperature, solid-liquid separation, washing, and drying to obtain the product; The mass ratio of the Ti3C2 MXene to ZnTCPP is 1:10-12; The Ti3C2 MXene is a single layer of Ti3C2; The solvent is N,N-dimethylformamide; The solvent thermal reaction is carried out in an inert gas atmosphere, wherein the inert gas is nitrogen; The organophosphorus pesticide is glyphosate.

2. The method for detecting organophosphorus pesticides using the nanoenzyme material Ti-ZnTCPP according to claim 1, wherein: The mass ratio of the Ti3C2 MXene to ZnTCPP is 1:

10.

3. The method for detecting organophosphorus pesticides using the nanoenzyme material Ti-ZnTCPP according to claim 1, wherein: The specific steps of the colorimetric detection include: Incubate acid phosphatase ACP and glyphosate of known concentration for 15-18 minutes to obtain a first mixed solution; Adding Ti-ZnTCPP and ascorbic acid 2-phosphate (AAP) to the first mixed solution, mixing evenly, and incubating for 15 to 18 minutes to obtain a second mixed solution; Add TMB to the second mixed solution, mix well, and detect the absorbance after irradiation for 15 to 20 minutes to establish a corresponding relationship between the absorbance value and the glyphosate concentration; Using glyphosate of unknown concentration to be tested, repeat the above steps, and determine the glyphosate concentration based on the detected absorbance value.

4. The method for detecting organophosphorus pesticides using the nanoenzyme material Ti-ZnTCPP according to claim 1, wherein: The specific steps of the photoelectrochemical detection include: Acid phosphatase ACP and glyphosate of known concentration were incubated for 15-18 minutes to obtain a mixed solution; The nanoenzyme material Ti-ZnTCPP and ascorbic acid-2-phosphate (AAP) were added to the mixture, mixed evenly, and incubated for 15 to 18 minutes. The cathode photocurrent intensity was detected under light, and a corresponding relationship between the cathode photocurrent intensity and the glyphosate concentration was established. Using glyphosate of unknown concentration to be tested, repeat the above steps, and determine the glyphosate concentration based on the detection of cathode photocurrent intensity.

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