The Preparation And Application Of Magnetic Micromotor Based On Spirulina Platensis

Micro/nanomotor is a kind of artificial motor which converts external driving forces such as electric energy,chemical energy and magnetic field to drive its own motion in the micro/nanometer range.Compared with chemical energy driven micro/nanomotor,it has the advantages of non-toxicity,simple fabrication,small size and easy operation.The motor driven by external magnetic field has attracted more and more attention.There are very broad application prospects in biological medicine and environmental remediation.In this paper,Fe₃O₄ nanoparticles were synthesized by chemical coprecipitation based on the advantages of artificial micro/nanomotors and the natural structure of Spirulina platensis.The magnetic spiral PDA@Fe₃O₄/Ag@Sp micromotor which has good biocompatibility was modified with polydopamine using its adhesion function and good reducibility and silver nanoparticles on the basis of Spirulina platensis.PDA@Fe₃O₄/Ag@Sp was characterized by XPS,XRD,SEM,TEM and ultra-depth-of-field microscopy.The results show that we have prepared a micromotor.XPS also confirmed the Fe₃O₄ nanoparticles,polydopamine and silver nanoparticles were deposited on the surface of Spirulina platensis.At the same time,the motor could use magnetic field to control its movement.The antimicrobial activity of PDA@Fe₃O₄/Ag@Sp micromotor against Escherichia coli was studied.The results show that when the concentration is 0.3μg/mL,the antimicrobial effect can be achieved within1 hour,the antimicrobial activity has high efficiency and recyclability,so it can play the role of sterilization,making it have great potential in biomedicine.Based on the preparation method of PDA@Fe₃O₄@Sp,a magnetic PDA@Fe₃O₄/Pd@Sp micromotor was prepared by utilizing the reductive ability of polydopamine to potassium chloropalladium chloride.It can catalyze the reduction of 4-nitrophenol with sodium borohydride.PDA@Fe₃O₄/Pd@Sp micromotor was characterized by XPS and XRD.The results showed that Pd nanoparticles were deposited on PDA@Fe₃O₄@Sp by reduction of polydopamine.In addition,we studied the catalytic activity of PDA@Fe₃O₄/Pd@Sp at different concentrations for 4-nitrophenol.With the increase of PDA@Fe₃O₄/Pd@Sp concentration,its catalytic effect is better,and PDA@Fe₃O₄/Pd@Sp could be separated,recovered and reused by magnet.At the same time,the micromotor has the advantages of high catalytic activity,high cycle stability,easy recovery and good universality.It has great application prospects in environmental governance.