Surface plasmon resonance biosensor based on integrated optical waveguide

We report a sensor based on spectral interrogation of surface plasmon resonance (SPR) in an integrated optical waveguide-coupled SPR sensing device. We present theoretical analysis of the integrated optical SPR sensor structure leading to a device design optimized for operation in aqueous environments. We demonstrate that the fabricated laboratory prototype of the sensor is capable of measuring bulk refractive index changes smaller than 1.2×10−6. In conjunction with specific biomolecular recognition elements (monoclonal antibodies against human chorigonadotropin (hCG)) the sensor is used for the detection of hCG. The sensor is demonstrated to be capable of detecting 2 ng of hCG present in 1 ml of 1% bovine serum albumin solution.