Preparation method of y2o3-co (oh) 2 particles and application thereof

Abstract

The application discloses a preparation method of Y2O3-Co(OH)2 particles and application thereof, and belongs to the technical field of material preparation. The preparation method of the Y2O3-Co(OH)2 particles is as follows: L-type amino acids containing amino and carboxyl functional groups are mixed with yttrium salt to perform microwave irradiation and heating reaction to obtain a eutectic solvent (y-DES); metal cobalt salt and an alkaline solution are sequentially added into the y-DES to continuously perform microwave irradiation and heating reaction until dissolution, and a brown mixed solution is obtained; solid-liquid separation is performed on the brown mixed solution after the reaction is completed, the precipitate is washed, and drying is performed to obtain the Y2O3-Co(OH)2 particles. The preparation method can realize accurate control of the morphology of the Y2O3-Co(OH)2 particles, and has the advantages of simple preparation process and no need of additional organic solvents. Through construction of a high-efficiency redox cycle system, the catalytic activity and the anti-interference ability are significantly enhanced, and efficient determination of organic phosphorus pesticides in acetylcholinesterase and inhibitor industrial wastewater is realized.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation technology, specifically relating to a method for preparing Y2O3-Co(OH)2 particles and their application. Background Technology

[0002] my country's annual industrial wastewater discharge exceeds 20 billion tons, with organophosphorus pesticide residues being a particularly prominent issue in wastewater from the chemical, pesticide, and pharmaceutical industries. For example, the organophosphorus concentration in the wastewater of a certain pesticide production enterprise can reach 1,000-5,000 mg / L, far exceeding the limit of 0.5 mg / L in the "Integrated Wastewater Discharge Standard" (GB8978-1996).

[0003] Organophosphorus pesticides (such as parathion and chlorpyrifos) in industrial wastewater are highly water-soluble, low in volatility, and bioaccumulative, easily penetrating water bodies to contaminate groundwater and soil. As neurotoxins, organophosphorus pesticides inhibit acetylcholinesterase, leading to abnormal nerve signal transduction and causing acute poisoning (such as respiratory distress and convulsions) and chronic diseases (such as Parkinson's disease and thyroid dysfunction). WHO data shows that of the 3 million people worldwide poisoned by organophosphorus pesticides each year, approximately 70% are related to exposure to industrial wastewater. The limitations of traditional technologies and policy needs have jointly driven the development of new detection methods, with enzyme-like technologies becoming a current research hotspot due to their unique advantages. Currently, enzyme-like materials face multiple challenges in synthesis and application. The complexity of their synthesis process, the potential risks posed by the use of organic solvents and biomolecules, and poor environmental tolerance severely restrict the development and promotion of this technology.

[0004] Many oxidase-like enzymes require precise temperature control for synthesis. Slight deviations in reaction conditions can lead to uneven particle size distribution and imperfect crystal forms, thus affecting their oxidase activity. Other oxidase-like enzymes require inert atmospheres and use organic reagents as solvents during synthesis. For some biomolecule-modified oxidase-like enzymes, the required biomolecules, such as specific proteins and nucleic acids, are complex and costly to obtain and purify. Furthermore, improper handling of these substances can cause long-term soil and water pollution. Simultaneously, the application of oxidase technology is greatly affected by environmental interference. For example, catalytic activity is extremely sensitive to temperature changes. When ambient temperature rises, the thermal motion of oxidase molecules intensifies, leading to the disruption of non-covalent bonds (such as hydrogen bonds and hydrophobic interactions) that maintain their spatial structure stability. This alters the conformation of the active site, resulting in a significant decrease in catalytic efficiency and even loss of activity. Strong oxidants or reducing agents in the environment can alter the valence state of metal ions or the state of redox-sensitive groups at the oxidase center, thereby destroying its function and causing loss of activity. Therefore, it is crucial to invent an oxidase-like material that is simple to synthesize, operates under mild conditions, and can adapt to complex environments for monitoring acetylcholinesterase and its inhibitors of organophosphorus pesticides in wastewater. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing Y2O3-Co(OH)2 particles and its application. This preparation method can achieve precise control of the morphology of Y2O3-Co(OH)2 particles, and the preparation process is simple and does not require the addition of additional organic solvents. Furthermore, by constructing an efficient redox cycle system, the catalytic activity and anti-interference ability are significantly enhanced, enabling the efficient determination of organophosphorus pesticides in industrial wastewater containing acetylcholinesterase and its inhibitors.

[0006] To achieve the objective of this invention, the present invention provides the following technical solution: a method for preparing Y2O3-Co(OH)2 particles, comprising the following steps:

[0007] (1) Mix L-type amino acids containing amino and carboxyl functional groups with metal yttrium salts and heat them with microwave radiation until a transparent solution is obtained to obtain a eutectic solvent (y-DES).

[0008] (2) Add the cobalt metal salt to the obtained y-DES and heat it under microwave radiation at 70~80℃ until it dissolves. Then add an alkaline solution and heat it to 90~100℃ for microwave radiation heating for 10~60 min to obtain a brown mixture.

[0009] (3) Separate the solid and liquid components of the brown mixture, wash the precipitate and dry it to obtain Y2O3-Co(OH)2 particles.

[0010] Furthermore, in step (1), the L-type amino acids containing amino and carboxyl functional groups include any one of L-glycine, L-alanine, and L-leucine, and the metal yttrium salt is any one of yttrium acetate tetrahydrate, yttrium nitrate tetrahydrate, and yttrium phosphate.

[0011] Furthermore, in step (1), the molar ratio of L-type amino acids containing amino and carboxyl functional groups to yttrium salt is 1:0.5~2, the microwave radiation heating reaction time is 2~6h, and the temperature is 80~100℃.

[0012] Furthermore, in step (2), the cobalt salt is any one of cobalt sulfate heptahydrate, cobalt phosphate octahydrate, and cobalt nitrate hexahydrate.

[0013] Furthermore, in step (2), the molar ratio of cobalt salt to yttrium salt is 1:0.5~2.

[0014] Furthermore, in step (2), the alkaline solution is one of sodium hydroxide solution, potassium hydroxide solution, or calcium hydroxide solution, and the concentration of the alkaline solution is 5-10M; the molar ratio of the alkali to the metal yttrium salt in the added alkaline solution is 1-2:1.

[0015] Another object of the present invention is to provide an application of the Y2O3-Co(OH)2 particles prepared by the above preparation method, based on their oxidase-like activity, for the detection of organophosphorus pesticides in industrial wastewater containing acetylcholinesterase and its inhibitors.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) The technical solution provided by this invention adopts a microwave radiation heating reaction method, which realizes efficient energy transfer of the reaction system through bulk heating. Compared with the traditional hydrothermal method, microwave energy acts directly on the interior of molecules, enabling the system to rapidly heat up to the reaction temperature within 10-60 minutes. At the same time, the penetrating heating characteristics of microwaves eliminate the temperature gradient problem caused by the lag in heat conduction in traditional methods, ensuring that the reactants are uniformly heated in three-dimensional space, significantly improving the uniformity of product morphology, and laying the foundation for industrial scale-up.

[0018] (2) The technical solution provided by this invention uses y-DES, which serves as both a solvent and a reactant and a template agent. Firstly, as a solvent, it completely replaces organic solvents. The unique hydrogen-bonded network structure of y-DES effectively dissolves precursors such as yttrium salts, forming a homogeneous and stable solution system. This ensures thorough mixing of all reaction components at the molecular level, greatly improving the uniformity of the reaction. Simultaneously, its extremely low volatility reduces solvent loss and environmental pollution during use. Secondly, as a template, y-DES can selectively adsorb onto specific crystal faces of the particles, controlling the growth rate and exposure ratio of the crystal faces. In the synthesis of Y2O3-Co(OH)2 particles, y-DES can promote the preferential growth of certain crystal faces, changing the relative proportion of crystal faces. For example, it increases the exposure ratio of crystal faces with higher catalytic activity (such as the {110} crystal face), thereby improving the overall catalytic performance of the particles. Characterization techniques such as XRD revealed significant changes in the intensity of certain diffraction peaks on the crystal planes of Y₂O₃-Co(OH)₂ particles under the action of the y-DES template, demonstrating the regulatory effect of y-DES on crystal plane growth. Finally, as a reactant, it directly participated in the synthesis of Y₂O₃-Co(OH)₂ particles. Organic components may undergo coordination reactions with metal ions to form stable intermediate complexes. These complexes can guide the aggregation and growth direction of metal ions in subsequent reactions, significantly influencing the final structure and properties of the particles. Taking the y-DES synthesized from L-glycine and yttrium nitrate tetrahydrate in Example 1 of this invention as an example, the guanidinyl group in L-glycine reacts with the Y-DES... 3+ Forming coordinate bonds, changing Y 3+ The electron cloud distribution and reactivity of the particles affect the crystallization process of Y2O3 in Y2O3-Co(OH)2 particles.

[0019] (3) The technical solution provided by this invention employs yttrium and cobalt salts, which significantly promote the redox cycle under the synergistic effect of the two metals, thus optimizing the reaction pathway of the detection process. During the detection process, Co(OH)2 is oxidized to a high-valence cobalt oxide by losing electrons, while Y2O3 can accept electrons to reduce the cobalt oxide back to Co(OH)2, while being oxidized itself. This redox cycle continues, greatly improving the catalytic conversion efficiency of the particles on substrates (such as products of acetylcholinesterase-catalyzed reactions).

[0020] (4) The technical solution provided by the present invention applies the prepared Y2O3-Co(OH)2 particles to detect acetylcholinesterase and its inhibitor organophosphorus pesticides in wastewater. The detection limit of acetylcholinesterase is calculated to be 0.069 mU / mL, and the detection limit of ethyl paraoxon, a representative organophosphorus pesticide, is 0.8 ng / mL. Compared with the prior art, this invention achieves a significant breakthrough with a lower detection limit. Attached Figure Description

[0021] Figure 1 This is a scanning electron microscope (SEM) image (5000x) of the Y2O3-Co(OH)2 particles in Example 1 of the present invention.

[0022] Figure 2 This is a SEM image (10000x) of the Y2O3-Co(OH)2 particles in Example 1 of the present invention.

[0023] Figure 3 This is an X-ray diffraction (XRD) pattern of the Y2O3-Co(OH)2 particles in Example 1 of the present invention;

[0024] Figure 4 The UV absorption spectrum of the Y2O3-Co(OH)2 particles in Example 1 of this invention is shown, with TMB selected as the substrate;

[0025] Figure 5 This is the ultraviolet absorption spectrum of Y2O3-Co(OH)2 particles in Example 1 of the present invention for detecting their antioxidant capacity. Y2O3-Co(OH)2+TMB was used as the analyte in all tests, and the test environment was high concentration of argon, air, and oxygen.

[0026] Figure 6 The UV absorption spectrum of Y2O3-Co(OH)2 particles used to detect acetylcholinesterase in Example 1 of this invention is shown.

[0027] Figure 7 This is the standard curve for detecting acetylcholinesterase using Y2O3-Co(OH)2 particles in Example 1 of this invention;

[0028] Figure 8 This is a comparison of UV absorption data when Y2O3-Co(OH)2 particles were used to detect acetylcholinesterase in Example 1 of this invention, with and without organophosphorus pesticides.

[0029] Figure 9 This is the standard curve of ethyl paraoxon, a representative model for detecting organophosphorus pesticides using Y2O3-Co(OH)2 particles in Example 1 of this invention.

[0030] Figure 10 This is the ultraviolet absorption spectrum of Y2O3-Co(OH)2 particles used in Example 1 of this invention for detecting their antioxidant properties;

[0031] Figure 11 This is a graph showing the comparison of the oxidase activity over time of Y2O3-Co(OH)2 particles synthesized by y-DES in Example 1 of the present invention, and Y2O3 and Co(OH)2 synthesized separately in Comparative Examples 1-3 and Y2O3-Co(OH)2 particles synthesized in water.

[0032] Figure 12 This is a SEM image of the Co(OH)2 particles synthesized in Comparative Example 1 of this invention.

[0033] Figure 13 This is a SEM image of the Y2O3 particles synthesized in Comparative Example 2 of this invention;

[0034] Figure 14 This is a SEM image of the Y2O3-Co(OH)2(H2O) particles synthesized in Comparative Example 3 of this invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto. In the following embodiments of the present invention, the microwave radiation device used is: ANKS-SR12 / 0~350°C, with a maximum output power of 1300W. Example 1

[0036] (1) Mix L-glycine (0.02 mol) and yttrium nitrate tetrahydrate (0.02 mol) and place them in a microwave radiation device. Heat the mixture at 100 °C for 6 h until a transparent solution is formed to obtain a eutectic solvent (y-DES).

[0037] (2) Take 8.4g of y-DES obtained in step (1), add 0.02mol of cobalt nitrate hexahydrate to it, and continue to heat it with microwave radiation at 80℃ until it dissolves; then add 7mL of 5M sodium hydroxide solution and heat it to 90℃ and continue to heat it with microwave radiation for 30min to obtain a brown mixture.

[0038] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it three times with water and ethanol, and dry it at 80°C for 12 hours to obtain Y2O3-Co(OH)2 particles. Example 2

[0039] (1) Mix L-alanine (0.02 mol) and yttrium phosphate (0.01 mol) in a microwave radiation device and heat them at 80 °C for 2 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0040] (2) Take 6g of y-DES obtained in step (1), add 0.02mol of cobalt sulfate heptahydrate to it, and continue to heat it with microwave radiation at 70℃ until it dissolves. Then add 2mL of 5M potassium hydroxide solution, raise the temperature to 100℃ and continue to heat it with microwave radiation for 10min to obtain a brown mixture.

[0041] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it 5 times with water and ethanol, and dry it at 90℃ for 12h to obtain Y2O3-Co(OH)2 particles. Example 3

[0042] (1) Mix L-leucine (0.02 mol) and yttrium acetate tetrahydrate (0.04 mol) in a microwave radiation device and heat the mixture at 90 °C for 4 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0043] (2) Take 13.2g of y-DES obtained in step (1), add 0.02mol of cobalt phosphate octahydrate to it, and continue to heat it with microwave radiation at 75℃ until it dissolves; then add 8mL of 10M calcium hydroxide solution, raise the temperature to 90℃ and continue to heat it with microwave radiation for 20min to obtain a brown mixture.

[0044] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it 4 times with water and ethanol, and dry it at 120℃ for 8 hours to obtain Y2O3-Co(OH)2 particles. Example 4

[0045] (1) Mix L-glycine (0.02 mol) and yttrium phosphate (0.02 mol) in a microwave radiation device and heat the mixture at 100 °C for 2 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0046] (2) Take 5.1g of y-DES obtained in step (1), add 0.02mol of cobalt nitrate hexahydrate to it, and continue to heat it with microwave radiation at 70℃ until it dissolves; then add 4mL of 5M sodium hydroxide solution and heat it to 95℃ and continue to heat it with microwave radiation for 40min to obtain a brown mixture.

[0047] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it 5 times with water and ethanol, and dry it at 110℃ for 10h to obtain Y2O3-Co(OH)2 particles. Example 5

[0048] (1) Mix L-alanine (0.02 mol) and yttrium nitrate tetrahydrate (0.02 mol) in a microwave radiation device and heat the mixture at 90 °C for 3 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0049] (2) Take 11.2g of y-DES obtained in step (1), add 0.02mol of cobalt sulfate heptahydrate to it, and continue to heat it with microwave radiation at 80℃ until it dissolves; then add 4mL of 5M sodium hydroxide solution and heat it to 90℃ and continue to heat it with microwave radiation for 50min to obtain a brown mixture.

[0050] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it 4 times with water and ethanol, and dry it at 90℃ for 10h to obtain Y2O3-Co(OH)2 particles. Example 6

[0051] (1) Mix L-glycine (0.02 mol) and yttrium nitrate tetrahydrate (0.02 mol) in a microwave radiation device and heat the mixture at 100 °C for 2 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0052] (2) Take 8.4g of y-DES obtained in step (1), add 0.02mol of cobalt nitrate hexahydrate to it, and continue to heat it with microwave radiation at 75℃ until it dissolves; then add 7mL of 5M potassium hydroxide solution, raise the temperature to 100℃ and continue to heat it with microwave radiation for 60min to obtain a brown mixture.

[0053] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it three times with water and ethanol, and dry it at 100℃ for 10h to obtain Y2O3-Co(OH)2 particles. Comparative Example 1

[0054] (1) Add 0.02 mol cobalt nitrate hexahydrate to 8.4 g of water and continue to heat the mixture with microwave radiation until it dissolves. The reaction time is 6 h and the temperature is 100 °C. Then add 7 mL of 5 M sodium hydroxide solution and continue to heat the mixture with microwave radiation for 30 min at 90 °C to obtain a light blue mixed solution.

[0055] (2) Cool the light blue mixture to room temperature, collect the brown precipitate by centrifugation, add water and ethanol three times, and dry at 80°C for 12 hours to obtain Co(OH)2 particles. Comparative Example 2

[0056] (1) Add 0.02 mol of yttrium nitrate tetrahydrate to 8.4 g of water, place it in a microwave radiation device, and continuously heat it at 100 °C for 6 h until it dissolves; then add 7 mL of 5 M sodium hydroxide solution to adjust the temperature to 90 °C and continue to heat it at 30 min to obtain a grayish-white mixture.

[0057] (2) Cool the grayish-white mixture to room temperature, collect the brown precipitate by centrifugation, add water and ethanol three times, and dry at 80°C for 12 hours to obtain Y2O3 particles. Comparative Example 3

[0058] (1) Add L-glycine (0.02 mol) and yttrium nitrate tetrahydrate (0.02 mol) to 8.4 g of water, place in a microwave radiation device, and microwave heat at 100 °C for 6 h;

[0059] (2) Then 0.02 mol of cobalt nitrate hexahydrate was added to it, and the reaction was carried out under microwave radiation at 80°C until it dissolved; then 7 mL of 5 M sodium hydroxide solution was added dropwise, the temperature was raised to 90°C and the reaction was carried out under microwave radiation for 30 min to obtain a brown mixture.

[0060] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it three times with water and ethanol, and dry it at 80°C for 12 hours to obtain Y2O3-Co(OH)2(H2O) particles. Comparative Example 4

[0061] (1) Mix L-proline (0.02 mol) and yttrium nitrate tetrahydrate (0.02 mol) in a microwave radiation device and heat the mixture at 100 °C for 6 h until a transparent liquid is formed, thus obtaining a eutectic solvent;

[0062] (2) Take 9.2g of y-DES obtained in step (1), add 7mL of 5mol / L sodium hydroxide solution to it, and heat it under microwave radiation at 90℃ for 30min to obtain a brown mixture.

[0063] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it repeatedly with water and ethanol, and dry it for 12 hours to obtain the precipitate. Comparative Example 5

[0064] (1) Mix L-glycine (0.02 mol) and cerium nitrate hexahydrate (0.02 mol) and place them in a microwave oven for radiation heating until a transparent liquid is formed. The reaction time is 6 h and the temperature is 100 °C, thus obtaining a eutectic solvent.

[0065] (2) Take 10g of y-DES obtained in step (1), add 7mL of 5mol / L sodium hydroxide solution to it, heat the mixture with microwave radiation for 30min, and the temperature is 90℃ to obtain a brown mixture.

[0066] (3) Cool the brown mixture to room temperature, collect the brown precipitate by centrifugation, wash it three times with water and ethanol, and dry it at 80°C for 12 hours to obtain the precipitate.

[0067] The Y2O3-Co(OH)2 particles obtained in Example 1 were used to conduct experiments on the detection of oxidase-like activity, acetylcholinesterase, organophosphorus pesticides in wastewater, mechanism investigation, and antioxidant capacity investigation.

[0068] Oxidase activity assay

[0069] For the oxidase activity experiment, 800 μL of HAc-NaAc buffer (100 mM, pH=4.4) and 100 μL of LY2O were mixed. 3- Co(OH)2 particles (1.0 mg / mL) were added sequentially to 1.5 mL centrifuge tubes, and then 100 μL TMB (10 mM) was added. After incubation at room temperature for 15 min, the absorbance at 652 nm was measured.

[0070] To compare the oxidase activity of different reaction systems of Y2O3-Co(OH)2 particles, 800 μL of HAc-NaAc buffer (100 mM, pH=4.4) was added to a 1.5 mL centrifuge tube. Then, 100 μL of each of the following were added: Y2O3, Co(OH)2, Y2O3-Co(OH)2 (H2O), and Y2O3-Co(OH)2 (y-DES), each at a concentration of 1.0 mg / mL. Finally, 100 μL of LMB (10 mM) was added. After mixing, the solutions were reacted in the same environment for the same amount of time, and the absorbance at 652 nm was measured to compare the strength of the oxidase activity.

[0071] Acetylcholinesterase detection

[0072] To detect acetylcholinesterase, the product of thiocholine, which hydrolyzes acetylcholine, can reduce the oxidation of TMB. First, 100 μL of 20 mU / mL acetylcholinesterase was added to 10 μL of phosphate buffer (100 mM, pH=8.0) containing 10 mM acetylcholine. After mixing thoroughly, the mixture was reacted at 37 °C for 30 min. Subsequently, 690 μL of HAc-NaAc buffer, 100 μL of LY2O3-Co(OH)2 particles (1.0 mg / mL), and 100 μL of TMB (10 mM) were added sequentially. After mixing, the mixture was reacted at room temperature for different times, and the absorbance of the solution at 652 nm was measured.

[0073] The hydrolysis of acetylcholine by acetylcholinesterase was optimized in this experiment. Experimental results showed that the optimal hydrolysis time was 30 min. The results demonstrated that the absorbance at 652 nm decreased with increasing acetylcholinesterase activity, and the decrease in absorbance at 652 nm showed a good linear relationship with the concentration of acetylcholinesterase in the range of 0.2-22 mU / mL. The calculated limit of detection for acetylcholinesterase was 0.069 mU / mL, indicating that this method has good sensitivity and is comparable to or better than the results reported in the literature.

[0074] Detection of organophosphorus pesticides in wastewater

[0075] The effect of reaction time between organophosphorus pesticides and acetylcholinesterase on the detection of organophosphorus pesticides: Two 100 µL aliquots of 180 mU / mL acetylcholinesterase were taken and mixed with 10 µL aliquots of organophosphorus pesticides of different concentrations (0.001 µg / mL) respectively. The mixtures were kept at 37 °C for different time periods, and then 10 µL of 10 mM acetylcholine was added to each aliquot. After thorough mixing, the mixtures were reacted at 37 °C for 30 min. Next, 680 µL of acetate buffer, 100 µL of LY₂O₃-Co(OH)₂ particles (1 mg / mL), and 100 µL of 10 mM TMB solution were added respectively, and the mixtures were incubated at 25 °C for 15 min. Finally, the absorbance at 652 nm was recorded.

[0076] Mechanism Investigation

[0077] To investigate the mechanism of Y₂O₃-Co(OH)₂ granular oxidase activity, after optimizing the experimental conditions, the optimal concentration of Y₂O₃-Co(OH)₂ granules was determined to be 1 mg / mL, with a TMB concentration of 10 mM, a reaction temperature of room temperature, a reaction buffer pH of 4.4, and a reaction time of 10 min. 800 μL of HAc-NaAc buffer (100 mM, pH=4.4) and 100 μL of Y₂O₃-Co(OH)₂ (1.0 mg / mL) were sequentially added to 1.5 mL centrifuge tubes, which were then placed in an ice bath at 0–4 °C. High-purity oxygen, argon, and air were bubbled through the tubes for 20 min each, with continuous agitation. Then, 100 μL of TMB (10 mM) was added, and the tubes were incubated at room temperature for 15 min before measuring the absorbance at 652 nm.

[0078] Exploring antioxidant capacity

[0079] The absorbance was measured after incubating 900 µL of DPPH (100 µM) and 100 µL of Y2O3-Co(OH)2 particles of different concentrations at room temperature in the dark for 30 min.

[0080] The following description, in conjunction with the accompanying drawings, explains the results of the above-mentioned testing experiments and investigations.

[0081] Figure 1 , 2 This is a SEM image of the synthesized Y2O3-Co(OH)2 particles. The results show that they are relatively regular triangular pyramidal in shape, and the particle surfaces are relatively smooth. Figure 1 However, at high resolution, some subtle textures or step structures may be visible. Figure 2 The diameter of the cone-shaped structure gradually decreases from the base to the tip, forming a natural concentration gradient-driven channel that can accelerate the mass transfer rate of target molecules (such as acetylcholine and organic pollutants) to the active site (2-5 times higher than that of the planar structure).

[0082] Figure 3 The XRD characterization diagram of Y2O3-Co(OH)2 particles describes the unique diffraction peaks contained in the Y2O3-Co(OH)2 particles. The experimental data shows that ~20.8°, ~24.7°, ~37.56°, ~50.94°, and ~59.65° belong to the (110), (210), and (211) crystal planes of Co(OH)2, respectively. At the same time, ~19.41°, ~29.25°, ~43.65°, and ~47.94° correspond to the (211), (222), (411), and (440) crystal planes of Y2O3, respectively. The 2θ angle of the diffraction peaks in the experimental spectrum is consistent with the peak position of the target material, and the deviation is within the allowable error range of the instrument. This strongly proves that the synthesized material has the same crystal structure as the target material and verifies the successful synthesis of Y2O3-Co(OH)2 particles.

[0083] Figure 4 The image shows the UV absorption spectrum of the Y₂O₃-Co(OH)₂ particles in Example 1 of this invention. TMB was selected as the chromogenic substrate for the investigation of oxidase-like activity. Figure 4 As shown, Y2O3-Co(OH)2 particles can catalyze the oxidation of colorless TMB to blue ox-TMB, with the maximum absorbance at 652 nm.

[0084] Figure 5 This is the UV absorption spectrum of Y₂O₃-Co(OH)₂ particles used in Example 1 of this invention for detecting their antioxidant capacity. The antioxidant capacity of Y₂O₃-Co(OH)₂ particles in Example 1 is essential for detecting organophosphorus compounds in wastewater. Y₂O₃-Co(OH)₂ particles prepared by γ-DES exhibit oxidase-like activity, and this oxidase-like antioxidant property can resist interference from other oxidizing or reducing substances in the wastewater. For example, the wastewater may contain some oxidizing heavy metal ions (such as Fe). 3+ Cu 2+Or other strong oxidants can attack the active site of oxidases, leading to enzyme inactivation. Similarly, organophosphorus compounds in the environment or during detection may generate free radicals. These free radicals can react with other substances in the detection system, interfering with the detection signal. The antioxidant properties of oxidases can promptly scavenge these free radicals, preventing damage to substrates, indicators, and other substances in the detection system. To investigate the effect of the gaseous environment on oxidase activity, we conducted a control experiment to verify whether the oxidase activity of Y₂O₃-Co(OH)₂ particles depends on oxygen. There was no significant difference in absorbance at 652 nm in saturated atmospheres of oxygen, air, and argon, indicating that the gaseous environment has little effect on the oxidase activity of Y₂O₃-Co(OH)₂ particles. Good oxidase activity can still be maintained in non-pure oxygen and inert gases, which is beneficial for subsequent applications.

[0085] Figure 6 The image shows the UV absorption spectrum of Y2O3-Co(OH)2 particles used to detect acetylcholinesterase in Example 1 of this invention. Thiocholine, a product of acetylcholinesterase hydrolyzing acetylcholine, can reduce the oxidation of TMB. As shown in the figure, when acetylcholinesterase and acetylcholine coexist, the absorbance of the system at 652 nm decreases significantly, indicating that the system can be used for the detection of acetylcholinesterase.

[0086] Figure 7 The standard curve for detecting acetylcholinesterase in Example 1 of this invention shows that the Y2O3-Co(OH)2 particles of this invention exhibit a linear relationship in the detection of acetylcholinesterase in the range of 0.2-22 mU / mL, with a wider linear range. Accurate determination can be achieved in a wider concentration range, and the detection limit can reach 0.069 mU / mL, indicating that the method has good sensitivity and is comparable to or better than the results reported in the literature.

[0087] Figure 8 This is a comparison of UV absorption in Example 1 of the present invention when Y₂O₃-Co(OH)₂ particles were used to detect acetylcholinesterase with and without organophosphorus pesticides. Organophosphorus pesticides are irreversible inhibitors of acetylcholinesterase. They can form covalent bonds with the active site of acetylcholinesterase, inhibiting its activity, leading to a reduction in the production of thiocholine and more TMB being catalyzed and oxidized by Y₂O₃-Co(OH)₂ particles. To explore the feasibility of using the Y₂O₃-Co(OH)₂ particle / TMB system for detecting organophosphorus pesticides, ethyl parathion was selected as the organophosphorus pesticide model. Figure 8 As shown, the absorbance of the system at 652 nm was restored when organophosphorus pesticides were present, and organophosphorus pesticides had no effect on the Y2O3-Co(OH)2 particle / TMB detection system.

[0088] Figure 9 This is the standard curve of ethyl paraoxon, a representative model for detecting organophosphorus pesticides using Y2O3-Co(OH)2 particles in Example 1 of the present invention. Experiments showed that the detection limit for ethyl paraoxon can reach 0.8 ng / mL.

[0089] Figure 10 This is the UV absorption spectrum of Y₂O₃-Co(OH)₂ particles used in Example 1 of this invention for detecting their antioxidant properties. The five colored curves represent the absorbance curves of 100 µL and 900 µL of DPPH (100 µM) solutions of five different concentrations of Y₂O₃-Co(OH)₂ particles after incubation at room temperature in the dark for 30 min. The blue curve represents a concentration of 1.0 mg / mL, the orange curve 0.8 mg / mL, the red curve 0.6 mg / mL, the purple curve 0.4 mg / mL, and the green curve 0.2 mg / mL. This test verifies the antioxidant capacity of the material. 1,1-Diphenyl-2-picrylhydrazide (DPPH) is most commonly used to evaluate the free radical scavenging ability of antioxidants. When Y₂O₃-Co(OH)₂ particles are present as an antioxidant, the hydrogen atoms they provide can combine with DPPH free radicals, causing the DPPH solution to lighten in color and enhancing UV absorption. As can be seen from the figure, the antioxidant properties of Y2O3-Co(OH)2 particles gradually increase with the increase of particle concentration, but even at the lowest concentration of 0.2 mg / mL, the antioxidant properties are still excellent.

[0090] Figure 11 This is a comparison graph showing the oxidase activity of Y2O3-Co(OH)2 particles synthesized by y-DES in Example 1 of this invention, and Y2O3, Co(OH)2 synthesized alone in Comparative Examples 1-3, and Y2O3-Co(OH)2 particles synthesized in water over time. As can be seen from the graph, the oxidase activity of all materials prepared increases with the increase of reaction time, but the increase of Y2O3-Co(OH)2 particles is the most significant. Thanks to the special reaction conditions created by y-DES and the synergistic effect between Y2O3 and Co(OH)2, the prepared bimetallic particle materials exhibit superior performance in the oxidase activity test.

[0091] Figure 12 The image shows a SEM image of the Co(OH)2 particles synthesized in Comparative Example 1 of this invention. As can be seen from the image, the Co(OH)2 particles synthesized alone have a disordered morphology, exhibiting microstructural characteristics of irregular orientation and uneven morphological distribution. It is impossible to synthesize a uniformly dispersed conical morphology, and thus it is impossible to increase the mass transfer rate.

[0092] Figure 13The image shows a SEM image of the Y2O3 particles synthesized in Comparative Example 2 of this invention. It was also found that individual Y2O3 particles could not form a conical morphology, but upon closer inspection, some cubic particles were found to be distributed among them, which is a characteristic morphology of Y2O3 particles.

[0093] Figure 14 The image shows a SEM image of the Y2O3-Co(OH)2(H2O) particles synthesized in Comparative Example 3 of this invention. Y2O3-Co(OH)2(H2O) synthesized alone in water cannot form a specific conical morphology, which proves that y-DES, as a template, selectively adsorbs on specific crystal faces of the particles, affecting the growth rate and morphology of the material.

[0094] Meanwhile, the experimental comparisons of the materials in Examples 1-6 and 1-5 of this invention are shown in Table 1:

[0095]

[0096]

[0097]

[0098] To test the sensitivity of the obtained materials, the materials prepared in the examples and comparative examples were tested and analyzed. Table 1 shows the detection limits of acetylcholinesterase and organophosphorus pesticides in Examples 1-6 and Comparative Examples 1-5. Figure 11 This table compares the oxidase-like activities of the materials obtained after the reactions of Example 1 and Comparative Examples 1-3. Experiments show that the detection limit for acetylcholinesterase in Example 1 reaches 0.069 mU / mL, and the detection limit for representative organophosphorus pesticides reaches 0.8 ng / mL. The detection sensitivity of the other examples does not reach this level. In Comparative Examples 1 and 2, Y₂O₃ particles and Co(OH)₂ alone showed no detection effect. This is largely attributed to the microwave penetrating heating characteristics in the Y₂O₃-Co(OH)₂ particle synthesis method, which facilitates the formation of morphological uniformity. Simultaneously, the solvent template effect of γ-DES forms a uniform cone-shaped morphology, creating an interfacial synergistic effect that increases the mass transfer rate of acetylcholinesterase or organophosphorus pesticide active sites. The specific structure optimizes the steric hindrance effect, reduces non-specific detection, and results in a lower signal-to-noise ratio and higher sensitivity.

[0099] Table 2 compares the methods for detecting acetylcholinesterase reported in this paper. The comparison shows that the detection limits of AuAgNCs and SiO2 materials for detecting acetylcholinesterase are 0.15 mU / mL and 200 mU / mL, respectively. The linear range of Y2O3-Co(OH)2 particles of this invention can reach 0.2-22 mU / mL. Within this wide range, the target concentration and the detection signal show good linearity, reducing the error caused by nonlinear fitting. It is especially suitable for samples with large concentration fluctuations. The detection limit is 0.06 mU / mL, which is much lower than the detection limits reported in the literature. It can identify low-concentration substances that cannot be detected by traditional methods, improving the accuracy and reliability of the analysis.

[0100] Table 3 compares the methods for detecting organophosphorus pesticides reported in this paper. The comparison reveals differences in Fe-N-CSAzymes and MnO. 2、 The detection limits for CeO2NPs materials were 0.97 ng / mL, 1.0 ng / mL, and 18.3 ng / mL, respectively. The detection limits for Y2O3-Co(OH)2 of this invention...

[0101] The linear range of particles can reach 0.0008-2 μg / mL. The wider the linear range, the stronger the applicability of the standard curve, and the more concentration range of actual samples it can cover. The detection limit is 0.8 ng / mL, which is much lower than the detection limit reported in the literature. It can identify low-concentration substances that cannot be detected by traditional methods and improve the sensitivity of detection.

Claims

1. A method for preparing Y2O3-Co(OH)2 particles, characterized in that, Includes the following steps: (1) Mix L-type amino acids containing amino and carboxyl functional groups with metal yttrium salts and heat them under microwave radiation until a transparent solution is formed to obtain a eutectic solvent; (2) Add the cobalt salt to the eutectic solvent and heat it under microwave radiation at 70~80℃ until it dissolves. Then add an alkaline solution and heat it to 90~100℃ for microwave radiation heating for 10~60 min to obtain a brown mixture. (3) Separate the solid and liquid components of the brown mixture, wash the precipitate and dry it to obtain Y2O3-Co(OH)2 particles; In step (1), the L-type amino acid containing amino and carboxyl functional groups is any one of L-glycine, L-alanine, and L-leucine; the metal yttrium salt is any one of yttrium acetate tetrahydrate, yttrium nitrate tetrahydrate, and yttrium phosphate. The Y2O3-Co(OH)2 particles are relatively regular triangular pyramidal in shape.

2. The method for preparing Y2O3-Co(OH)2 particles according to claim 1, characterized in that, In step (1), the molar ratio of L-type amino acids containing amino and carboxyl functional groups to yttrium salt is 1:0.5~2, the microwave radiation heating reaction time is 2~6h, and the temperature is 80~100℃.

3. The method for preparing Y2O3-Co(OH)2 particles according to claim 1, characterized in that, In step (2), the cobalt salt is any one of cobalt sulfate heptahydrate, cobalt phosphate octahydrate, or cobalt nitrate hexahydrate.

4. The method for preparing Y2O3-Co(OH)2 particles according to claim 1, characterized in that, In step (2), the molar ratio of cobalt salt to yttrium salt is 1:0.5~2.

5. The method for preparing Y2O3-Co(OH)2 particles according to claim 1, characterized in that, In step (2), the alkaline solution is one of sodium hydroxide solution, potassium hydroxide solution, or calcium hydroxide solution, the concentration of the alkaline solution is 5~10M, and the molar ratio of the alkali to the metal yttrium salt in the added alkaline solution is 1~2:

1.

6. An application of Y2O3-Co(OH)2 particles prepared by the preparation method according to any one of claims 1-5, characterized in that, It was used to detect organophosphorus pesticides in industrial wastewater from acetylcholinesterase and its inhibitors.

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