The electrorotation of microspheres coated with conductive surface is a novel and important technology for label-free biosensors. Using the electroless plating approach, the polystyrene microspheres with 15 μm and 25...The electrorotation of microspheres coated with conductive surface is a novel and important technology for label-free biosensors. Using the electroless plating approach, the polystyrene microspheres with 15 μm and 25 μm in diameters were coated with 50 nm gold layer in thickness. The electrorotation experiments on those gold coated polystyrene microspheres (GCPMs) were carried out. The results showed that they rotated in the opposite direction of the electric field in a low frequency range (100-100 kHz), and the maximum rotation speed was higher than that of uncoated microspheres. Based on the theory of traveling wave electroosmosis(TWEO) and induced charge electroosmosis (ICEO), the electrorotation of GCPMs was quantitively analyzed and confirmed by observing the fluid flow around GCPM. The equations describing the electroration speed of GCPMs were proposed, which are consistent with the experiment results.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51075087)the State Key Lab of Fluid Power Transmission and Control of ZheJiang University (Grant No. GZKF-201004)+1 种基金the China Scholarship Council (Grant No. 2009612129)Program for New Century Excellent Talents in University (Grant No. NCET-09-0054)
文摘The electrorotation of microspheres coated with conductive surface is a novel and important technology for label-free biosensors. Using the electroless plating approach, the polystyrene microspheres with 15 μm and 25 μm in diameters were coated with 50 nm gold layer in thickness. The electrorotation experiments on those gold coated polystyrene microspheres (GCPMs) were carried out. The results showed that they rotated in the opposite direction of the electric field in a low frequency range (100-100 kHz), and the maximum rotation speed was higher than that of uncoated microspheres. Based on the theory of traveling wave electroosmosis(TWEO) and induced charge electroosmosis (ICEO), the electrorotation of GCPMs was quantitively analyzed and confirmed by observing the fluid flow around GCPM. The equations describing the electroration speed of GCPMs were proposed, which are consistent with the experiment results.
