Preparation And Application Of Natural Enzyme/nanozyme Composite Micro/nanomotor

Micro-and nano-sized motors（MNMs）are devices that can convert external energy or chemical energy into mechanical energy to drive themselves.By designing them with specific functional components combined with efficient liquid mass transfer in the micro field,they have shown great application prospects in various fields such as environmental governance and biological detection.Natural enzymes are proteins,RNA,or complexes that catalyze specific chemical reactions.Nanozymes are a type of simulated artificial enzyme that have nanomaterials and catalytic function characteristics.They are stable,multifunctional,economical,and can be prepared on a large scale.Using natural enzymes/nanozymes as catalysts to provide power and function for micro-nanomotors is an innovative approach.Compared with traditional chemical catalytic micro-nanomotors,they have good biocompatibility,which is of great value in environmental and biological fields.This paper aims to prepare multifunctional micro-nanomotors using natural enzyme-nanomotor compounds in response to the increasingly serious problem of drugs contamination.It innovatively combines the autonomous movement of micro-motors with the properties and characteristics of various enzymes to realize multifunctional combinations of identification,detection,adsorption,and degradation of drug residues in water.Lac-Mn₃O₄/Ni Co-LDH micromotors and Ag-Fe₃O₄/GOx@ZIF-8 Janus nanomotors were prepared,and their motion behaviors in H₂O₂ and glucose solutions,as well as their performance in drugs detection,adsorption,and degradation,were studied as follows:The Lac-Mn₃O₄/Ni Co-LDH Janus spherical micromotors with a micro-nano composite multi-level structure were prepared using hydrothermal calcination to prepare Ni Co-MOF as a sacrificial template.The micromotors were etched,in situ REDOX and crosslinked to create a dual-function platform for color detection and removal of o-methoxyphenol.The Mn₃O₄catalyzed H₂O₂ to produce bubbles,propelling the micromotors through the reaction force.The velocity was positively correlated with the concentration of H₂O₂,reaching up to 117.8μm s^-1in a 5 wt%H₂O₂ solution.The Ni Co-LDH with peroxidase-like activity catalyzes the decomposition to produce·OH,which,in collaboration with the oxidase-like properties of laccase,can oxidize the chromogenic substrate TMB,achieving sensitive detection of ortho-methoxyphenol with a detection limit of 0.043μM.Copper ions in laccase further improved the catalytic activity of phenols,and the Fenton-like catalytic activity of Ni Co-LDH degraded o-methoxyphenol into environmentally friendly small molecules,achieving 91.7%removal at p H4.The Lac-Mn₃O₄-Ni Co-LDH Janus spherical micromotors combined the specific properties of laccase and Mn₃O₄ nanozyme with the self-driving properties of the micromotors,promoting the diffusion and intermolecular collision probability of the catalytic micro-platform in the reaction environment,achieving dynamic detection and rapid degradation of guaiacol.To improve the adverse impact on the environment caused by excessive H₂O₂ solution which decomposes reactive oxygen species,we designed and synthesized Ag-Fe₃O₄/GOx@ZIF-8 Janus nanomotors using biocompatible glucose solution as the starting point to solve the problem of slow movement of low concentration H₂O₂ solution in the previous system.The nanomotor was applied to tetracycline hydrochloride（TCH）adsorption and photo-Fenton degradation.By combining glucose oxidase（GOx）,Fe₃O₄,and Ag nanozyme,endogenous H₂O₂ was fully utilized to drive micromotors and adsorb and degrade TCH through a cascade reaction.The p H-dependent enzyme properties of Ag nanozyme were used to achieve switching control from adsorption to degradation of micromotors.The ZIF-8 nanoparticles containing GOx and Fe₃O₄ were prepared by one-step coprecipitate method,and then Ag⁺in Ag NO₃ was reduced by a wet chemical method with a low concentration reducing agent to form a Janus structure on the GOx/Fe₃O₄@ZIF-8 side.This unique Janus structure enabled the nanomotors to achieve a more concentrated bubble reaction force,with diffusion coefficients up to 19.53μm² s^-1 in 1 mol L^-1 glucose solution（p H 7）.The zeolite imidazole lipid skeleton of ZIF-8 provided adhesion sites for adsorption of TCH,and the maximum adsorption capacity of Ag-Fe₃O₄/GOx@ZIF-8 was 104.65 mg g^-1.With the help of ultraviolet light,the catalytic performance of Ag and Fe₃O₄ photo-assisted Fenton effectively degraded TCH,achieving a removal rate of 99.1%of TCH in 1 mol L^-1 glucose solution.The micromotor achieved functional conversion by changing p H,attributed to the strong catalytic performance of natural enzymes-nanozyme in coordination with the autonomous motion characteristics of the nanomotor,effectively improving the removal efficiency of TCH antibiotics.