Sensitivity enhancement of SPR biosensor by improving surface quality of glass slides

Surface plasmon resonance (SPR) is one of the most sensitive label-free detection methods and has been applied in a wide range of chemical and biological sensing. Sensitivity enhancement of metal coated sensor chips is necessary for improving the detection limit of SPR biosensor. The roughness effect of glass surface on sensitivity is usually ignored. Glass slides with different roughness values were prepared by polishing and measured with atomic force microscope (AFM). The response curves of the gold coated glass slides were obtained by using SPR biosensor. The intrinsic sensitivity (IS) of the sample with RMS-roughness of 2.02 nm is 15.26, while that of the samples with RMS-roughness values of 1.4 nm and 1.31 nm are increased by 58.1% and 48.6%. Higher sensitivity and narrower response curves for SPR biosensors are achieved by improving surface quality of glass slides. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.