Preparation Of Polymeric Tubular Micromotor And Its Application For Biosensing

Artificial micro/nanomotors,a class of synthetic micromachines,have received increasing attention over the past decade.Among these motors,polymer/Pt motors are particularly attractive owing to their efficient movement in various environments.Unfortunately,the motion performance of the catalytic motors commonly suffers great loss in protein-rich system or after motor modification with receptors owing to the surface passivation of the Pt layer,[1,2]which results in low detection sensitivity and thus limits their practical application in biological systems.In addition,Most of the aforesaid motor-based biosensors rely on measuring changes in the speed of unloaded catalytic motors induced by sandwich nano/micro tags capture,which requires sophisticated fabrication and high cost.To solve these problems,the research of this work is as follows:1.Preparation of polymeric micromotor doped with Pt nanoparticle@carbon nanotube for Complex Bio-mediaA highly efficient polymeric tubular micromotor is fabricated by template-assisted electrochemical growth of poly(3,4-ethylenedioxythiophene)and Pt nanoparticles-carbon nanotube doped polypyrrole(PtNP@CNT-PPy).By using the PtNP@CNT as a catalyst to decompose hydrogen peroxide fuel,the micromotor shows good motion performance at low-level fuel(62 ?m s-1 at 1%H2O2),and in ionic-strength solution,human serum,cell culture solution,particularly,protein-rich system(52 ?m s-1 in 1 mM bovine serum albumin at 2%H2O2).Furthermore,the effect of micromotor functionalization with receptors on motion speed is negligible.Its motion direction is magnetically controllable by co-depositing Fe3O4 nanoparticles in PtNP@CNT-PPy layer.The polymeric micromotor has been used to capture and transport E.coli in biological environment.It shows the advantages of simple and mass preparation,easy modification,and good biocompatibility,indicating good promise for biological application.2.Preparation of Motor-based DNA BioprobeHere,a motor-based bioprobe is designed relying on the asymmetric catalase modification occurring on the surface of the micromaterial via chemical bonding and DNA in-situ assembly technology.By the addition of target DNA,the catalase can be released from the motor surface,which leads to a loss of motion performance.The velocity of the motor-based bioprobe is related to the concentration of target DNA,thus a real-time,fast,label-free DNA dynamic sensing detection method is established easily.