Poly(2-hydroxyethyl methacrylate) (PHEMA) was grafted from initiator-immobilized gold surfaces via activator generated by electron transfer atom transfer radical polymerization (AGET ATRP) to repel nonspecific protein adsorption and immobilize biotin for specific avidin binding.The surface polymerization of HEMA was demonstrated by FTIR and contact angle measurements.The bioinertness of the PHEMA-modified surfaces was systematically studied.125I-labeled protein (Fg

HSA and Lys) adsorption experiments showed that modification with PHEMA could decrease nonspecific protein adsorption by 82% at least.Cell adhesion results indicated that the Au-PHEMA surface could

to a great extent

resist the adhesion of L929

L02 and endothelium cell (EC).L929 showed slight adhesion while L02 and EC could not adhere at all.PHEMA-biotin modified surfaces with varied PHEMA thickness were prepared with different reaction time

and all these surfaces showed good nonspecific protein-repellant property.In the specific FITC-avidin adsorption experiments

the fluorescence was undetectable when the thickness of PHEMA was below 16 nm due to fluorescence quenching.The fluorescence increased with the thickness between 16 nm and 49 nm.The best signal-to-noise ratio was obtained when the thickness was above 49 nm.The optimized PHEMA-biotin surface performed quite well in the QCM and fluorescence bio-detections and showed potential applications as a substrate of biochip.