Surface plasmon resonance based silicon-chip biosensor is proposed for the detection of different human blood groups in near infrared region. The plasmonic structure based on silicon glass chip is suitable for simple and accurate low volume blood-group detection. Experimental results describing the wavelength-dependent refractive index variation of different blood groups are considered for theoretical calculations. The results are explained in terms of light coupling and plasmon resonance condition. The sensor's performance is closely analyzed in terms of its angular shift and curve width in order to predict the design considerations enabling precise blood-group identification. The proposed low-volume blood-group biosensor chip can be very useful in medical application.
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.