Self-assembly Of Enzyme-loaded Colloidosome Micromotors Based On Droplet Template And Preliminary Study On Their Performance

Micro-nano motors（MNMs）are bionic micro-nano functional devices that can transform chemical energy or other forms of energy into their own mechanical movement.They have been successfully applied in the fields of drug delivery,biosensing,environmental remediation and so on.Therefore,in order to meet the demands of these applications,we need develop ways to control the direction and speed of MNMs.However,precise control of small motors is difficult due to low Reynolds numbers and the effect of Brownian motion.At present,the methods to regulate MNMs motion behavior have some problems,such as the need for accurate operation in the field and the difficulty to adjust the motion state of the motors according to its own structure.In this paper,based on the droplet template method,enzyme-loaded colloidosome micromotors are fabricated to control of the motion by changes in micro/nano structure.Furthermore,their applications in enhancing adsorption and enhancing enzymatic reaction are studied.In the synthesis and characterization of the enzyme-loaded colloidosome micromotors,this study successfully fabricate the enzyme-loaded colloidosome micromotors by the droplet-templated method,and explore the formation mechanism of the structure of stomatocyte.It is proved that the enzyme can be effectively loaded between the shells of the colloidosomes and the encapsulation rate can reach more than 90%.It is confirmed that the micromotors has excellent retention of enzyme activity,up to 90.97%.The enzyme-loaded colloidosome micromotors provide a new idea for the development of novel enzyme-powered MNMs.In the part of the study on the motion performance of micromotors,the author specially design micromotors with different micro-nano structures,which is an internal control strategy to control speed of motors by regulating the micro-nano structure of the motor itself.In the same substrate hydrogen peroxide（2%）solution,the maximum speed of the micromotor is 191μm·s^-1 formed by self-assembly of 22 nm colloidal particles,while the speed of the micromotor formed by 12 nm and 7 nm colloidal particles are 56μm·s^-1 and 29μm·s^-1,respectively.Finally,the author also successfully construct the magnetically responsive enzyme-loaded SiO₂/Fe₃O₄colloidosome micromotors to achieve accurate navigation of the motors.This study provides a new approach for motion control of MNMs.In the part of the study on the enhancement of mass transfer performance of the enzyme-loaded colloidosome micromotors,two experiments are designed to prove that the enhancement of mass transfer process can be controlled by adjusting the structure of the micromotors without changing the external environment.By changing the self-assembly conditions,the micromotors with different pore sizes are prepared,and the mass transfer process is regulated and strengthened by changing the motion rate.In the enhanced adsorption reaction,when MB is used as the model dye,the removal efficiency of the micromotor prepared by 22 nm nanoparticles is 93%,while the removal efficiency of the micromotor formed by 12 nm and 7nm nanoparticles decreased successively,which are 89%and 84%,respectively.In the enhanced catalytic reaction part,the study find that the efficiency of chelating CO₂sequestration by micromotors loaded with double enzymes prepared by 22 nm nanoparticles reach 89.8%within 5 min,while the efficiency of sequestration by 12 nm and 7 nm nanoparticles are 72%and 51%.The micromotors prepared by this system is expected to provide a simple and feasible solution for water purification and greenhouse effect.