A recyclable peroxidase mimetic enzyme and its preparation method and application

Abstract

The present invention belongs to the field of catalysts, and specifically relates to a recyclable peroxidase mimetic enzyme, its preparation method, and application. The peroxidase mimetic enzyme comprises PVA aerogel and CuO nanoparticles, wherein the CuO nanoparticles are loaded on the surface of the PVA aerogel. The preparation method comprises sequentially immersing the PVA aerogel in a copper salt solution and an alkaline solution, washing, and drying the aerogel to obtain the peroxidase mimetic enzyme. The peroxidase mimetic enzyme prepared by the present invention not only has excellent catalytic performance, but is also easy to recycle and separate after the catalytic reaction, can be reused, and still maintains good catalytic performance after repeated recycling ten times. Moreover, when the peroxidase mimetic enzyme is removed during the catalytic reaction, the reaction rate is significantly reduced, achieving the effect that the reaction can be controlled at any time. In addition, the peroxidase mimetic enzyme can achieve highly sensitive and instant detection of hydroquinone / catechol, has a simple operation process, does not require specialized instruments and professionals, greatly improves detection speed, and reduces labor costs.

Description

Technical Field

[0001] The invention belongs to the field of catalysts, and in particular relates to a recyclable peroxidase mimetic enzyme and a preparation method and application thereof. Background Art

[0002] Nanozymes are nanomaterials with properties similar to those of natural enzymes, capable of participating in specific biocatalytic processes. Since Yan et al. first discovered that magnetic Fe₃O₄ mimics peroxidases, nanozymes have attracted widespread attention due to their low cost, wide availability, stable performance, and ease of mass production. Among the various nanozymes, copper oxide, a non-toxic transition metal oxide, offers excellent properties such as widespread availability, low cost, and diverse morphologies.

[0003] Although nanozyme catalysts exhibit high catalytic activity and selectivity in homogeneous solutions, they also have the problem of short lifespan. In addition, most nanozymes will disperse in the reaction solution after use, which makes the recovery and reuse of nanozymes very difficult. Compared with homogeneous reactions, catalyst immobilization has the advantages of direct catalyst recovery, easy material separation, and simple post-processing. Selecting a suitable carrier can solve the problem of difficult recovery of nanozymes after participating in the reaction. Aerogel has high porosity and is very suitable as a catalyst carrier. Polyvinyl alcohol aerogel is an inexpensive polymer with good chemical stability, good mechanical properties, and low biological toxicity. In addition, its surface has rich groups that can be further functionalized. Therefore, polyvinyl alcohol aerogel is a suitable nanozyme loading material.

[0004] Water is the source of life and a good solvent. It plays a vital role in life activities, social development, energy production, and industrial manufacturing. Therefore, protecting water resources and the environment is crucial for sustainable development. Dihydroxyphenol compounds are widely used in medicine, cosmetics, dyes, leather making, pesticides, photography, and chemical industries. They often enter the environment through wastewater discharge. They are Class II pollutants and are harmful to both humans and the environment. Among them, hydroquinone and catechol are two important isomers of dihydroxyphenol. Excessive intake of hydroquinone can cause dizziness, headaches, and even kidney damage, while catechol can cause liver problems. They are highly toxic to the ecological environment and have low degradability. Measuring their content is crucial for maintaining the ecological environment and protecting human health. Summary of the Invention

[0005] In view of the problems and shortcomings in the prior art, the present invention aims to provide a recyclable peroxidase mimetic enzyme and its preparation method and application.

[0006] To achieve the purpose of the invention, the technical solution adopted by the present invention is as follows:

[0007] A first aspect of the present invention provides a peroxidase mimetic enzyme, which comprises PVA aerogel and CuO nanoparticles, wherein the CuO nanoparticles are loaded on the surface of the PVA aerogel.

[0008] The second aspect of the present invention provides a method for preparing the peroxidase mimetic enzyme described in the first aspect, comprising soaking the PVA aerogel in a copper salt solution and an alkaline solution in sequence, washing and drying the aerogel after soaking, to obtain the peroxidase mimetic enzyme.

[0009] According to the above-mentioned method for preparing the peroxidase mimetic enzyme, preferably, the method for preparing the PVA aerogel is: dissolving maleic acid in a polyvinyl alcohol solution to obtain a mixed solution; adding concentrated sulfuric acid to the mixed solution, reacting at 180-220°C, and filtering, washing, and drying after the reaction to obtain the PVA aerogel.

[0010] According to the above-mentioned method for preparing peroxidase mimetic enzyme, preferably, the concentration of the copper salt solution is 0.1-1.5 mol / L, the concentration of the alkaline solution is 0.5-1.5 mol / L, and the concentration of the polyvinyl alcohol solution is 5-10 wt%.

[0011] According to the above-mentioned method for preparing peroxidase mimetic enzyme, preferably, the copper salt is any one of copper chloride, copper sulfate or copper nitrate, most preferably copper chloride; and the alkaline solution is sodium hydroxide solution or potassium hydroxide solution, most preferably sodium hydroxide solution.

[0012] According to the above-mentioned method for preparing the peroxidase mimetic enzyme, preferably, the mass ratio of the polyvinyl alcohol to maleic acid is 1 to 2:1.

[0013] The third aspect of the present invention provides a use of the peroxidase mimetic enzyme described in the first aspect in detecting hydrogen peroxide.

[0014] According to the above-mentioned application of the peroxidase mimetic enzyme in the detection of hydrogen peroxide, preferably, the process of detecting hydrogen peroxide is: the peroxidase mimetic enzyme described in the first aspect of the present invention, the color developer 3,3',5,5'-tetramethylbenzidine (TMB) solution, and the hydrogen peroxide sample to be tested are added in sequence to a buffer solution with a pH value of 3 to 5, the reaction is carried out at 20 to 60° C. for 5 to 20 minutes, and the absorbance at 652 nm is measured using an ultraviolet spectrophotometer.

[0015] The principle behind the peroxidase-mimicking enzyme for hydrogen peroxide detection is that the PVA-CuO prepared in the present invention catalyzes hydrogen peroxide to produce hydroxyl radicals under acidic conditions. These hydroxyl radicals react with colorless TMB to form blue oxidized TMB (i.e., oxTMB), causing a color change in the solution. oxTMB has a maximum absorption at 625 nm. As the hydrogen peroxide concentration increases, the absorbance of oxTMB at 625 nm gradually increases. Therefore, quantitative detection of hydrogen peroxide concentration can be achieved by scanning the UV-visible spectrum.

[0016] The fourth aspect of the present invention provides a use of the peroxidase mimetic enzyme described in the first aspect in detecting hydroquinone or catechol.

[0017] According to the above-mentioned use of the peroxidase mimetic enzyme in the detection of hydroquinone or catechol, preferably, the process of detecting hydroquinone or catechol is: the peroxidase mimetic enzyme described in the first aspect of the present invention, the color developer 3,3',5,5'-tetramethylbenzidine (TMB) solution, and the hydrogen peroxide solution are sequentially added to a buffer solution with a pH value of 3 to 5 to obtain a mixed solution; then the hydroquinone sample or catechol sample to be tested is added to the mixed solution, the reaction is carried out at 20 to 40° C. for 20 to 40 minutes, and the absorbance at 652 nm is measured using an ultraviolet spectrophotometer.

[0018] The schematic diagram of the principle of the above peroxidase mimicking enzyme to detect hydroquinone or catechol is as follows Figure 1 As shown, the PVA-CuO prepared by the present invention catalyzes hydrogen peroxide under acidic conditions to produce hydroxyl radicals. These hydroxyl radicals react with colorless TMB to form blue oxidized TMB (i.e., oxTMB). Since hydroquinone (i.e., HQ) or catechol (i.e., CC) are reducing, they react with the blue oxTMB, causing the solution to gradually fade. oxTMB has a maximum absorption at 625 nm. As the concentration of hydroquinone or catechol increases, the absorbance of oxTMB at 625 nm gradually decreases. The change in absorbance is linearly related to the concentration of hydroquinone or catechol. Therefore, quantitative detection of the concentration of hydroquinone or catechol can be achieved by scanning the UV-visible spectrum.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) Traditional nanozymes disperse in the reaction solution after use, making them difficult to recycle. The present invention utilizes a method of PVA aerogel-loaded copper oxide nanozyme to prepare a recyclable peroxidase mimetic enzyme PVA-CuO. The peroxidase mimetic enzyme not only has excellent catalytic performance, but is also easy to recycle and separate after the catalytic reaction, can be reused, and maintains good catalytic performance after repeated recycling ten times. In addition, when the peroxidase mimetic enzyme prepared by the present invention is removed during the catalytic reaction, the reaction rate is significantly reduced, achieving the effect of being able to control the reaction at any time.

[0021] (2) The preparation method of the peroxidase mimetic enzyme described in the present invention is simple, has abundant raw materials, a short preparation cycle, and low overall cost, and is an efficient and feasible method.

[0022] (3) The peroxidase prepared by the present invention can achieve highly sensitive and immediate detection of hydroquinone and catechol. The operation process is simple, and no specialized instruments or professionals are required. The detection sensitivity is high, which greatly improves the detection speed and reduces labor costs. In addition, the peroxidase can be recycled and reused after use to avoid environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the principle of detecting hydroquinone or catechol by the peroxidase mimetic enzyme of the present invention;

[0024] Figure 2 A schematic diagram of the process for preparing a peroxidase mimetic enzyme according to the present invention;

[0025] Figure 3 This is a SEM image of the peroxidase mimetic enzyme PVA-CuO prepared in Example 1 of the present invention;

[0026] Figure 4 XRD patterns of the PVA aerogel obtained in step (1) of Example 1 of the present invention, the PVA-CuO prepared in Example 1, and commercially available CuO;

[0027] Figure 5 FT-IR images of the PVA aerogel obtained in step (1) of Example 1 of the present invention, the PVA-CuO prepared in Example 1, and commercially available CuO;

[0028] Figure 6 This is the full XPS spectrum of the peroxidase mimetic enzyme PVA-CuO prepared in Example 1 of the present invention;

[0029] Figure 7 The relative activity diagram of PVA-CuO catalyzing TMB prepared in Examples 1, 2, 3, and 4 of the present invention;

[0030] Figure 8The relative activity diagram of the recyclability of PVA-CuO prepared in Test Example 1 of the present invention;

[0031] Figure 9 This is a UV-visible scanning spectrum diagram of the catalytic effect of PVA-CuO and CuO tested in the present invention;

[0032] Figure 10 This is a UV-visible scanning spectrum diagram of the controllable catalytic performance of PVA-CuO tested in the present invention;

[0033] Figure 11 This is the signal diagram of hydroquinone / catechol inhibiting oxTMB during the detection of hydroquinone / catechol by PVA-CuO;

[0034] Figure 12 This is the linear relationship between the absorbance value at 625 nm and the different concentrations of hydroquinone detected by PVA-CuO;

[0035] Figure 13 This is the linear relationship diagram of PVA-CuO detection of different concentrations of catechol and the absorbance value at 625nm. DETAILED DESCRIPTION

[0036] The following examples are intended only to further illustrate the present invention. It should be noted that all technical and scientific terms used herein have the same meanings as in the art to which the present invention pertains, unless otherwise specified. Experimental methods in the following examples, where specific conditions are not specified, were based on conventional techniques in the art or the conditions recommended by the manufacturer. Reagents and instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0037] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0038] Example 1

[0039] Prepare a peroxidase mimetic enzyme PVA-CuO, the process diagram is as follows Figure 2 As shown, the specific steps include:

[0040] (1) 0.77 g of polyvinyl alcohol powder was dissolved in 11 mL of water. 0.508 g of maleic acid was added to the solution and stirred in a 95°C oil bath until dissolved. After dissolution, 1 mL of 18 mol / L concentrated sulfuric acid was added dropwise to the solution while stirring. The reaction solution was then transferred to a 75 mL hydrothermal reactor and reacted at 200°C for 24 h. After the reaction was completed, the product was filtered, washed, and dried to obtain PVA aerogel.

[0041] (2) Cut the PVA aerogel into 0.005g block cubes, soak them in 20mL 1mol / L copper chloride solution overnight, take out the cubes and dry them in an 80℃ oven. Transfer the dried cubes to a clean beaker, add a small amount of NaOH (1mol / L) to submerge the cubes, soak them for 8h, take them out and dry them in an 85℃ oven, then wash them with pure water and anhydrous ethanol in turn, and dry them again. Repeat the above NaOH immersion, drying, washing and drying again steps to obtain the peroxidase mimetic enzyme PVA-CuO with a black surface.

[0042] Example 2

[0043] The content of Example 2 is substantially the same as that of Example 1, except that the concentration of the cupric chloride solution in step (2) is 0.1 mol / L.

[0044] Example 3

[0045] The content of Example 3 is substantially the same as that of Example 1, except that the concentration of the cupric chloride solution in step (2) is 0.5 mol / L.

[0046] Example 4

[0047] The content of Example 4 is substantially the same as that of Example 1, except that the concentration of the cupric chloride solution in step (2) is 1.5 mol / L.

[0048] Example 5

[0049] The preparation of peroxidase mimetic enzyme PVA-CuO comprises the following steps:

[0050] (1) 0.55 g of polyvinyl alcohol powder was dissolved in 11 mL of water. 0.508 g of maleic acid was added to the solution and stirred in a 95°C oil bath until dissolved. After dissolution, 1 mL of 18 mol / L concentrated sulfuric acid was added dropwise to the solution while stirring. The reaction solution was then transferred to a 75 mL hydrothermal reactor and reacted at 180°C for 24 h. After the reaction was completed, the product was filtered, washed, and dried to obtain PVA aerogel.

[0051] (2) Cut the PVA aerogel into 0.005g block cubes, soak them in 20mL 1.5mol / L copper chloride solution overnight, take out the cubes and dry them in an 80℃ oven. Transfer the dried cubes to a clean beaker, add a small amount of NaOH (0.5mol / L) to submerge the cubes, soak them for 8h, take them out and dry them in a 75℃ oven, then wash them with pure water and anhydrous ethanol in turn, and dry them again. Repeat the above NaOH immersion, drying, washing and drying again steps to obtain the peroxidase mimetic enzyme PVA-CuO with a black surface.

[0052] Example 6

[0053] The preparation of peroxidase mimetic enzyme PVA-CuO comprises the following steps:

[0054] (1) Dissolve 1 g of polyvinyl alcohol powder in 11 mL of water. Add 0.508 g of maleic acid to the solution and stir in a 95°C oil bath until dissolved. After dissolution, add 1 mL of 18 mol / L concentrated sulfuric acid dropwise to the solution while stirring. Then transfer the reaction solution to a 75 mL hydrothermal reactor and react at 220°C for 24 h. After the reaction is complete, filter, wash, and dry the product to obtain PVA aerogel.

[0055] (2) Cut the PVA aerogel into 0.005g block cubes, soak them in 20mL 1mol / L copper chloride solution overnight, take out the cubes and dry them in an 80℃ oven. Transfer the dried cubes to a clean beaker, add a small amount of NaOH (1.5mol / L) to submerge the cubes, soak them for 8h, take them out and dry them in a 90℃ oven, then wash them with pure water and anhydrous ethanol in turn, and dry them again. Repeat the above NaOH immersion, drying, washing and drying again steps to obtain the peroxidase mimetic enzyme PVA-CuO with a black surface.

[0056] (1) Structural characterization of PVA-CuO products

[0057] 1. SEM images of PVA-CuO

[0058] The scanning electron microscope image of the peroxidase mimetic enzyme PVA-CuO prepared in Example 1 is as follows: Figure 3 As shown. Figure 3 It can be seen that the PVA-CuO product has a porous morphology and its surface is rough due to the growth of CuO nanoparticles, indicating that the CuO nanoparticles have been successfully immobilized on the surface of PVA aerogel.

[0059] 2. XRD pattern of PVA-CuO

[0060] The XRD patterns of the PVA aerogel obtained in step (1) of Example 1, the PVA-CuO prepared in Example 1, and the commercially available CuO are shown in FIG. Figure 4 As shown, from Figure 4 It can be seen that the main characteristic peaks of CuO nanoparticles (002), (111) and (100) lattice planes appear in the PVA-CuO product, which indicates the successful preparation of PVA-CuO.

[0061] 3. IR spectrum of PVA-CuO

[0062] The IR spectra of the PVA aerogel obtained in step (1) of Example 1, the PVA-CuO prepared in Example 1, and the commercially available CuO are shown in FIG. Figure 5 As shown, from Figure 5 It can be seen that three new bands of CuO nanoparticles appear in the FT-IR spectrum of PVA-CuO, which are located at 432.3 cm -1 、497cm -1 and 603.3cm -1 The characteristic band of PVA-CuO is located at 849 cm -1 、1632cm -1 and 3420cm -1 , which correspond to the C-C stretching vibration, C=C stretching vibration and -OH group of PVA aerogel, respectively. The above results indicate that the crystal phase of CuO nanoparticles and the molecular structure of PVA aerogel can be well maintained during the synthesis of PVA-CuO.

[0063] 4. Full XPS spectrum of PVA-CuO

[0064] The XPS full spectrum of the peroxidase mimetic enzyme PVA-CuO prepared in Example 1 is as follows: Figure 6 As shown, from Figure 6 It can be seen that the spectrum measured by full X-ray photoelectron spectroscopy (XPS) shows the presence of Cu, O and C elements in PVA-CuO.

[0065] (2) Catalytic performance test of PVA-CuO products

[0066] 1. Comparison of the catalytic properties of PVA-CuO products obtained when PVA aerogels were soaked in copper chloride at different concentrations

[0067] 0.005 g of each of the PVA-CuO products prepared in Examples 1, 2, 3, and 4 and 0.005 g of the PVA aerogel obtained in step (1) of Example 1 were taken, and the five groups of products were mixed with 20 μL of 0.1 MH2O2 solution, 200 μL of 10 mM TMB (3,3',5,5'-tetramethylbenzidine) solution, and 2 mL of buffer (1×0.02 MHAc-NaAc, pH=4.0) to obtain a reaction solution; the reaction solution was incubated at 30° C. for 30 minutes, and then the absorption spectrum was measured using a UV-4802 spectrophotometer in the wavelength range of 400-800 nm, and the maximum absorption value at a wavelength of 652 nm was recorded. The results are as follows: Figure 7 As shown, Figure 7 middle

[0068] from Figure 7It can be seen that the catalytic effects of PVA-CuO prepared using 1 mol / L and 1.5 mol / L copper chloride solutions are not much different. Considering the dosage and benefits, the present invention prefers 1 mol / L copper chloride solution.

[0069] 2. Testing the recyclability of PVA-CuO

[0070] Take 0.005g of the PVA-CuO product prepared in Example 1, 20μL of 0.1MH2O2 solution and 200μL of 10mMTMB (3,3',5,5'-tetramethylbenzidine) solution, add them to 2mL of buffer solution (1×0.02MHAc-NaAc, pH=4.0) and mix to obtain a reaction solution; incubate the reaction solution at 30°C for 30 minutes, and then use a UV-4802 spectrophotometer to measure the absorption spectrum in the wavelength range of 400-800nm, and record the maximum absorption value at a wavelength of 652nm. After the measurement, separate the PVA-CuO from the reaction solution and wash the PVA-CuO with ultrapure water to remove the residual solution on the surface. Continue the test with the same piece of PVA-CuO and repeat the above test ten times. The results are as follows Figure 8 As shown, Figure 8 middle

[0071] from Figure 8 It can be seen that PVA-CuO can catalyze the color development reaction of TMB solution. After 10 cycles of use, PVA-CuO can still maintain 58.4% of its catalytic activity. This experiment shows that the peroxidase mimetic enzyme PVA-CuO prepared by the present invention has excellent recyclability.

[0072] 3. Comparison of the catalytic effects of PVA-CuO and CuO

[0073] The PVA-CuO product prepared in Example 1, 20 μL of 0.1MH2O2 solution, and 200 μL of 10 mM TMB (3,3',5,5'-tetramethylbenzidine) solution were added to 2 mL of buffer (1×0.02MHAc-NaAc, pH=4.0) and mixed to obtain a reaction solution. The reaction solution was incubated at 30°C for 30 minutes, and then the absorption spectrum was measured using a UV-4802 spectrophotometer in the wavelength range of 400 to 800 nm, and the maximum absorption value at a wavelength of 652 nm was recorded.

[0074] In order to show that the catalytic effect of PVA-CuO is better, the PVA-CuO product in the above test method was replaced by PVA aerogel and CuO as the control group, and a blank control group (TMB+H2O2) was set up. The results are as follows Figure 9 shown.

[0075] from Figure 9 It can be seen that compared with the blank control group, PVA aerogel has basically no catalytic effect on the mixed solution of H2O2 and TMB, while the reaction rate is significantly improved when PVA-CuO or CuO is used as a catalyst. The above results show that the peroxidase-like activity derived from CuO is perfectly inherited by PVA-CuO, which makes PVA-CuO have good catalytic performance in promoting peroxidation reactions. It is worth noting that CuO cannot be recycled when used as a catalyst in this reaction system, while the PVA-CuO prepared by the present invention can be recycled and reused while achieving the same catalytic effect, greatly reducing the detection cost.

[0076] 4. Testing the Controllable Catalytic Properties of PVA-CuO

[0077] In order to verify the controllable catalytic performance of PVA-CuO, 2 mL of buffer solution (1×0.02 M HAc-NaAc, pH=4.0), 20 μL of H2O2 (0.1 M) and 200 μL of TMB (10 mM) solution were added to a test tube to obtain a mixed solution. The PVA-CuO prepared in Example 1 was then immersed in the mixed solution and reacted at 30°C. After 10 minutes, the PVA-CuO was taken out from the reaction solution, and the reaction solution was allowed to continue to react at 30°C. After 20 minutes, the PVA-CuO was put into the reaction solution again, and after 10 minutes of catalytic reaction, the PVA-CuO was taken out again. This process of adding / taking out PVA-CuO was repeated four times. During this period, the reaction solution was kept incubated at 30°C, and the absorbance of the reaction solution at a wavelength of 652 nm was recorded every 2 minutes. The results are shown in FIG. Figure 10 shown.

[0078] like Figure 10 As shown in Figure 2, during the test, when PVA-CuO was immersed in the solution to activate the catalysis, the absorption value of the oxTMB indicator increased sharply within each 10-minute interval. When PVA-CuO was separated from the TMB-H2O2 solution to hinder the catalysis, the absorption value of the oxTMB indicator increased relatively slowly within each 20-minute interval ( Figure 10 This proves that the catalytic reaction and efficiency of PVA-CuO can be artificially regulated, and the reaction can be controlled at any time.

[0079] (III) Application of PVA-CuO products in the detection of hydroquinone / catechol solutions

[0080] 1. Testing the detection effect of PVA-CuO prepared in Example 1 on a series of concentrations of hydroquinone / catechol solutions

[0081] 0.005 g of the PVA-CuO product prepared in Example 1 was mixed with 2 mL of reaction buffer (1×0.02 M HAc-NaAc, pH=4.0), 20 μL of H2O2 (100 mM) solution, and 200 μL of TMB (10 mM) solution. Subsequently, 100 μL of hydroquinone (HQ) or catechol (CC) aqueous samples of various concentrations were added. The mixture was incubated in a water bath at 30° C. for 30 minutes. The absorption spectrum was then measured using a UV-4802 spectrophotometer within the wavelength range of 400-800 nm, and the maximum absorption value at a wavelength of 652 nm was recorded. The results are shown in FIG. Figure 11 、 Figure 12 、 Figure 13 shown.

[0082] Figure 11 The signal diagram of hydroquinone / catechol inhibiting oxTMB is shown in Figure 2. Figure 11 It can be seen that after adding hydroquinone (HQ) water sample or catechol (CC) water sample to the mixed solution, the absorption intensity of oxTMB indicator is significantly reduced.

[0083] Figure 12 The linear relationship diagram of different concentrations of hydroquinone and the absorbance value at 625nm is shown in Figure 2. Figure 13 The linear relationship between different concentrations of catechol and the absorbance at 625 nm is shown in Figure 2. Figure 12 and Figure 13 As can be seen, the absorbance of the oxTMB indicator at 652 nm gradually decreases with increasing concentrations of hydroquinone or catechol, and the change in absorbance shows a good linear relationship with the concentration of hydroquinone or catechol between 0 and 150 μM. The lower limit of detection (LOD) for hydroquinone is 0.084 μM (3σ / k), and the lower limit of detection (LOD) for catechol is 0.101 μM (3σ / k). These results demonstrate that the PVA-CuO product prepared by the present invention exhibits a considerable linear range and sensitivity in the detection of hydroquinone or catechol.

[0084] 2. Testing the PVA-CuO prepared in Example 1 for detecting hydroquinone / catechol in tap water, lake water, and industrial wastewater

[0085] Tap water and lake water from Guangxi University, as well as industrial wastewater from a ChronChemicals reagent factory, were filtered through a 0.22 μm membrane to remove solid particles, yielding three water samples. To verify the feasibility of the PVA-CuO method described herein for detecting hydroquinone in actual samples, hydroquinone was spiked into each of the three water samples at concentrations of 1 μM, 50 μM, and 100 μM, respectively. Spiked recovery tests were conducted on the hydroquinone samples at different concentrations, and the results are shown in Table 1.

[0086] Table 1 Recovery results of spiked water samples with different concentrations of hydroquinone

[0087]

[0088] As shown in Table 1, the spiked recoveries for tap water samples ranged from 93.58% to 114.24%, with standard deviations ranging from 2.44% to 10.06%. The spiked recoveries for lake water samples ranged from 98.66% to 104.37%, with standard deviations ranging from 1.36% to 2.36%. The spiked recoveries for industrial wastewater samples ranged from 92.17% to 99.86%, with standard deviations ranging from 1.43% to 6.16%. These results demonstrate that, compared to traditional analytical instruments, detection based on the PVA-CuO catalyst can provide a reliable method for on-site analysis of real samples.

[0089] The above embodiments are specific implementation methods of the present invention, but the implementation methods of the present invention are not limited to the above embodiments. Any other combination, change, modification, substitution, and simplification that does not exceed the design concept of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A peroxidase mimetic enzyme, characterized in that The peroxidase mimicking enzyme comprises PVA aerogel and CuO nanoparticles, wherein the CuO nanoparticles are loaded on the surface of the PVA aerogel. The loading process comprises: sequentially immersing the PVA aerogel in a copper salt solution and an alkaline solution, washing and drying the aerogel after immersion, and repeating the alkaline solution immersion, drying, washing and drying steps again to obtain the peroxidase mimicking enzyme.

2. A method for preparing the peroxidase mimetic enzyme according to claim 1, characterized in that: The PVA aerogel is sequentially immersed in a copper salt solution and an alkaline solution, and then washed and dried. The alkaline solution soaking, drying, washing and drying steps are repeated to obtain the peroxidase mimicking enzyme.

3. The method for preparing the peroxidase mimetic enzyme according to claim 2, wherein The preparation method of the PVA aerogel comprises the following steps: dissolving maleic acid in a polyvinyl alcohol solution to obtain a mixed solution; adding concentrated sulfuric acid to the mixed solution, reacting at 180-220° C., and filtering, washing, and drying the mixed solution after the reaction is completed to obtain the PVA aerogel.

4. The method for preparing the peroxidase mimetic enzyme according to claim 3, wherein The concentration of the copper salt solution is 0.1-1.5 mol / L, the concentration of the alkali solution is 0.5-1.5 mol / L, and the concentration of the polyvinyl alcohol solution is 5-10 wt %.

5. The method for preparing the peroxidase mimetic enzyme according to claim 4, wherein The copper salt is any one of copper chloride, copper sulfate or copper nitrate; and the alkaline solution is sodium hydroxide solution or potassium hydroxide solution.

6. The method for preparing the peroxidase mimetic enzyme according to claim 4, wherein The mass ratio of the polyvinyl alcohol to maleic acid is 1-2:

1.

7. Use of the peroxidase mimetic enzyme according to claim 1 in detecting hydrogen peroxide.

8. The use according to claim 7, characterized in that The process of detecting hydrogen peroxide is as follows: the peroxidase mimetic enzyme according to claim 1, the color developing agent 3,3',5,5'-tetramethylbenzidine solution, and the hydrogen peroxide sample to be tested are sequentially added to a buffer solution with a pH value of 3 to 5, reacted at 20 to 60° C. for 5 to 20 minutes, and the absorbance at 652 nm is measured using an ultraviolet spectrophotometer.

9. Use of the peroxidase mimetic enzyme according to claim 1 in detecting hydroquinone or catechol.

10. The use according to claim 9, characterized in that The process for detecting hydroquinone or catechol is as follows: the peroxidase mimetic enzyme according to claim 1, a color developer 3,3',5,5'-tetramethylbenzidine solution, and a hydrogen peroxide solution are sequentially added to a buffer solution with a pH value of 3 to 5 to obtain a mixed solution; then, a hydroquinone sample or catechol sample to be tested is added to the mixed solution, reacting at 20 to 40° C. for 20 to 40 minutes, and measuring the absorbance at 652 nm using an ultraviolet spectrophotometer.

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