A method for synthesizing a nanozyme with laccase-like activity based on manganese compounds

Abstract

The present invention discloses a method for synthesizing a nanozyme with laccase-like activity based on a manganese compound. Laccase is a polyphenol oxidase containing four copper ions, and water is generated after the reaction, so it is essentially an environmentally friendly enzyme. Therefore, laccase can be used as a green catalyst in water treatment, soil bioremediation and other aspects. However, due to high cost, poor stability in complex environments, and difficult recovery, the practical application of laccase is seriously hindered. Compared with traditional bioenzymes, nanozymes have better environmental stability, low cost, recyclability, and easy processing. The content of this invention patent relates to a method for synthesizing a nanozyme with laccase-like activity based on a manganese compound. The nanozyme with laccase-like activity based on a manganese compound synthesized by the present invention exhibits better catalytic activity and stability than biological laccase. This method has the advantages of simple operation and simple procedure.

Description

Technical Field

[0001] The present invention relates to the fields of manganese compounds and nanozymes, and specifically to a method for synthesizing nanozymes with laccase-like activity based on manganese compounds. Background Art

[0002] Laccase is a polyphenol oxidase containing four copper ions, and water is generated after the reaction, so it is essentially an environmentally friendly enzyme. Therefore, laccase can be used as a green catalyst in water treatment, soil bioremediation and other aspects. However, due to high cost, poor stability in complex environments, and difficult recovery, the practical application of laccase has been seriously hindered. Compared with traditional bioenzymes, nanozymes have better environmental stability, low cost, recyclability, and easy processing. The content of this invention patent relates to a method for synthesizing nanozymes with laccase-like activity based on manganese compounds. Summary of the Invention

[0003] The content of this invention patent relates to a method for synthesizing nanozymes with laccase-like activity based on manganese compounds. The nanozymes with laccase-like activity are simply referred to as laccase nanozymes in the present invention. This method has the advantages of simple operation and simple procedure.

[0004] Further, the nanozymes with laccase-like activity based on manganese compounds described in this patent are also called laccase nanozymes based on manganese compounds;

[0005] Further, the manganese compounds described in this patent include, but are not limited to, Mn3O4, MnCaO2, MnO2, and other manganese- and oxygen-containing compounds;

[0006] Further, the manganese compounds described in this patent include, but are not limited to, single compounds among Mn3O4, MnCaO2, MnO2, and other manganese- and oxygen-containing compounds;

[0007] Further, the manganese compounds described in this patent include, but are not limited to, mixed manganese compounds composed of two or more compounds among MnO2, Mn3O4, MnCaO2, and other manganese- and oxygen-containing compounds;

[0008] Further, the nanozymes with laccase-like activity based on manganese compounds described in this patent include, but are not limited to, single compounds among MnO2, Mn3O4, MnCaO2, and other manganese- and oxygen-containing compounds, or mixed manganese compounds of two or more of them;

[0009] Furthermore, the nanozyme with laccase-like activity based on manganese compounds described in this patent includes, but is not limited to, a single compound among MnO2, Mn3O4, MnCaO2, and other manganese- and oxygen-containing compounds, or a composite material composed of a mixture of two or more of these manganese compounds and other materials;

[0010] Furthermore, the manganese compound or mixed manganese compounds described in this patent form a composite material with other materials, and the other materials include, but are not limited to, graphene and its derivatives, carbon nanotubes and their derivatives, or other materials that can be used as carrier materials for manganese compounds or mixed manganese compounds.

[0011] Furthermore, the manganese compound or mixed manganese compounds described in this patent form a composite material with other materials, which is a material in which the manganese compound or mixed manganese compounds and other materials are combined or connected to each other through covalent bonding, adsorption, hydrogen bonding, hydrophilic interaction, hydrophobic interaction, or van der Waals force, or a combination of some or all of these interactions. Description of the Drawings

[0012] Figure 1 . The activities of two nanozymes with laccase-like activity based on manganese compounds (Mn3O4 / rGO and MnCaO2) were verified by three different methods.

[0013] (A) ABTS method. Laccase can decompose the substrate ABTS to produce ABTS radicals (ABTS*), and the product has a characteristic absorption peak at 420 nm. The activity of laccase is characterized by the change in absorbance value. [ABTS]: 0.93 mM; [Mn3O4 / rGO] and [MnCaO2]: 0.33 mg / mL. ABTS = 2,2'-Azinobis-(3-ethylbenzthiazoline-6- ), 2,2'-azino-bis- -6- ) diammonium salt.

[0014] (B) Bisphenol A-4-aminoantipyrine colorimetric method; Bisphenol A (BPA) and 4-aminoantipyrine (4-AP) undergo a typical color reaction under the action of laccase, and an obvious absorption peak appears at 510 nm. [BPA]: 0.32 mM; [4-AP]: 8 mM.

[0015] (C) Syringaldazine method. The activity of laccase was characterized by improving the test method for laccase activity of Merck. Specifically, under the action of laccase, it reacts with Syringaldazine, and the change in the absorbance of the solution after 10 min of reaction is measured at 530 nm. [Syringaldazine]: 0.22 mM; [Mn3O4 / rGO] and [MnCaO2]: 0.33 mg / mL. Detailed implementation mode

[0016] The following combines the synthesis of two laccase nanozymes based on manganese compounds to show specific embodiments of the present invention.

[0017] (1) Preparation of Mn3O4 / rGO as a laccase nanozyme: Specifically, a certain amount of graphene oxide was fully dispersed with ethanol, and a certain amount of manganese acetate was dissolved in water. Then, the manganese acetate aqueous solution, ammonia water, and water were mixed, and the graphene oxide dispersion was added. The mixture was vigorously stirred at 60 - 120 °C for 10 hours, transferred to a reaction kettle, and reacted at 100 - 180 °C for 3 hours. The product was washed with water and ethanol and dried in vacuo at 60 °C to obtain the Mn3O4 / rGO nanozyme.

[0018] (2) Preparation of MnCaO2 as a laccase nanozyme: Specifically, a certain amount of calcium chloride and manganese acetate were respectively dissolved in water and mixed to obtain solution A. Potassium permanganate and potassium hydroxide were mixed to obtain a hot solution B. Solutions A and B were mixed and vigorously stirred to form a dark precipitate, and stirring was continued for 2 hours to obtain a suspension, which was centrifuged, washed, dried at 50 - 80 °C for 12 hours, and then calcined at 300 - 600 °C for 10 hours to finally obtain the MnCaO2 nanozyme.

Claims

1. A method for synthesizing a nanozyme with laccase-like activity based on manganese compounds, characterized in that, The manganese compound-based laccase nanozyme is a manganese compound containing calcium and oxygen, namely MnCaO2, which is prepared by the following method: Dissolve a certain amount of calcium chloride and manganese acetate in water respectively, and mix them to obtain solution A. Mix potassium permanganate and potassium hydroxide to obtain a hot solution B. Mix solutions A and B, stir to generate a dark precipitate, continue stirring to obtain a suspension, centrifuge, wash, dry, and calcine at high temperature in air to finally obtain a nanozyme with laccase-like activity and a composition of MnCaO2.

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