Surface plasmon resonance biosensor based on integrated optical waveguide

We report a sensor based on spectral interrogation of surface plasmon reson ance (SPR) in an integrated optical waveguide-coupled SPR sensing device. W e present theoretical analysis of the integrated optical SPR sensor structu re leading to a device design optimized for operation in aqueous environmen ts. We demonstrate that the fabricated laboratory prototype of the sensor i s capable of measuring bulk refractive index changes smaller than 1.2 x 10( -6). In conjunction with specific biomolecular recognition elements (monocl onal antibodies against human chorigonadotropin (hCG)) the sensor is used f or the detection of hCG. The sensor is demonstrated to be capable of detect ing 2 ng of hCG present in 1 mi of 1% bovine serum albumin solution. (C) 20 01 Elsevier Science B.V. All rights reserved.