Optical heterodyne surface plasmon resonance biosensor

Abstract

A novel optical heterodyne surface plasmon resonance (SPR) biosensor using Zeeman laser is proposed. There are two surface plasma waves (SPWs) being excited by two correlated P polarized waves in an SPR device of Kretschmann configuration. The two reflected P waves are optically heterodyned so that the amplitude of the heterodyned signal is proportional to the multiplication of two attenuated reflected P waves. The detection sensitivity and the dynamical range based on this amplitude sensitive method are enhanced. In the experiment, the kinetics between mouse IgG and anti-mouse IgG is obtained according to the sensograms of different concentrations of anti-mouse IgG. The detection sensitivity corresponding to 0.2 nM is achieved. In addition, a concentration of 5 ng/ml of protein G interacting with mouse IgG is measured successfully.