Fabrication Of Laccase-Powered Nanomotors Towards The Efficient Degradation Of Multiple Pollutants

During the past decade,micro/nano motors have shown a wide range of applications in sewage treatment and have attracted the attention of scientists from all over the world.However,the requirement for additional fuel and the removal of single contaminant remained as two major challenges when micro/nanomotors were utilized for environmental remediation.To solve the current problems,laccase powered nanomotors were orchestrated for the first time to deal with multiple pollutants simultanously without adding additional fuel.Firstly,the nanomotor body was prepared with Fe₃O₄ nanoparticles as the core and mesoporous silica as the shell,due to its easy modification.Then,3-aminopropyltriethoxysilane and glutaraldehyde were used as coupling agents to modify the surface to achieve the immobilization of laccase,thus the laccase-powered nanomotors were constructed,with the characterization and analysis on the preparation process and products in each step.Secondly,the laccase-powered motors were used to degrade a variety of representative pollutants from industrial wastewater in situ.The degradation process demonstrated enhanced Brownian motion in bisphenol A,Congo red solutions and their mixture.The diffusion coefficients of laccase nanomotors in bisphenol A solution increase from 0.35±0.01μm²s^-1 to 1.16±0.02μm²s^-1,and increase from 0.35±0.01 to 1.4±0.03μm²s^-1 in Congo red solution.This movement speeds up with the increase of the pollutant concentration,and plateaus when the substrate concentration reaches the maximum enzyme reaction rate.Thirdly,lipase was introduced onto the surface of the laccase-powered motors to expand the types of potentially degraded pollutants.Compared with the laccase-powered motors,the catalytic reaction of the two enzymes on the motors at the same time shows a more efficient movement behavior on the motor.The diffusion coefficient of lipase-assisted laccase motors in the mixed solution of bisphenol A and triacetin increased to 1.3±0.03μm²s^-1,and increased to1.53±0.04μm²s^-1 when added into the mixed solution of Congo red and triacetin.Finally,we investigated the degradation process of multiple pollutants in the sewage and demonstrated the degradation of bisphenol A,Congo red,and the completely degradation of triacetin within 40 minutes,with good stability,circulation,and high efficiency.This study has demonstrated for the first time that the laccase-based catalytic reaction can be utilized to trigger the enhanced Brownian motion of nanomotors in laccase substrates,and realized the efficient degradation of pollutants in sewage.The lipase-assisted laccase-powered motors were effectively to expand the types of degraded pollutants.Therefore,this work expands the application and opens the new ways of micro/nanomotors in the field of environmental remediation.