A new surface plasmon resonance sensor for high-throughput screening applications

We report a new high-throughput surface plasmon resonance (SPR) sensor based on combination of SPR imaging with polarization contrast and a spatially patterned multilayer SPR structure. We demonstrate that this approach offers numerous advantageous features including high-contrast SPR images suitable for automated computer analysis, minimum crosstalk between neighboring sensing channels and inherent compensation for light level fluctuations. Applications of a laboratory prototype of the high-throughput SPR sensor with 108 sensing channels for refractometry and biosensing are described. In refractometric experiments, the noise-limited refractive index resolution of the system has been established to be 3 × 10−6 refractive index unit (RIU). Experimental data on detection of human choriogonadotropin (hCG) suggest that in conjunction with monoclonal antibodies against hCG, the reported SPR imaging sensor is capable of detecting hCG at concentrations lower than 500 ng/ml.