Surface plasmon resonance sensors utilizing rnicrofabricated channels

Surface plasmon resonance (SPR) scanning and imaging measurements have many applications in chemical and biological sensing. In this paper, we have us ed SPR to study protein adsorption onto chemically modified gold surfaces. We present a method for using a patterned photobiotin probe in microfluidic channels for sensing proteins with SPR. Each flow cell in a chip is 15 mum x 90 mum x 6 mm, giving a sample volume of 8 nl. The flow cell is created using conventional photolithographic and etching techniques, employing an a dhesive UV resin to hold a fused silica coverslip in place. To improve the selectivity and label proteins, photobiotin patterns are modified by UV ill umination at 365 nm. onto self-assembled monolayers (SAMs) of cysteamine on gold in the fluidic channels. The specific adsorption of the protein avidi n onto the photobiotin layer is monitored with the SPR scanning technique, which is extremely sensitive to the index of refraction of the adjacent med ium. (C) 2001 Elsevier Science B.V. All rights reserved.