Development of a sensitive SPR biosensor for C-reactive protein (CRP) using plasma-treated parylene-N film

Parylene-N film has high protein immobilization property after plasma-treatment. In this work, the optimum conditions for plasma-treatment of parylene-N films were investigated to develop a highly sensitive SPR biosensor. The effects of the plasma power and plasma-treatment time on the surface of parylene-N films were analyzed by measuring film contact angle and roughness from atomic force microscopy images. The plasma power was applied at a range of 0-100W for different treatment times. The influence of plasma-treatment was also analyzed using the depth profiles from X-ray photospectroscopy. From this analysis, chemical functional groups (those related to oxygen) were introduced and were estimated to penetrate up to 4 nm and 8 nm from the top surface of the parylene-N film due to treatment with plasma powers of 50W and 100W, respectively, for 1 min. Based on the optimum plasma-treatment conditions for the plasma power and the plasma-treatment time, an SPR biosensor was developed for the detection of the human C-reactive protein. (C) 2014 Elsevier B.V. All rights reserved.