Surface plasmon resonance spectro-imaging sensor for biomolecular surface interaction characterization

Abstract Surface plasmon resonance (SPR) techniques have become, over the last ten years, powerful tools to study biomolecular surface interaction kinetics in real-time without any use of labels. The highest resolution is currently obtained using spectroscopic SPR systems through the measurement of the complete surface plasmon resonance curve in angular or spectral configuration. But, these systems are limited to a few independent channels ( y -dimension) by a white light source. The reflected light spectrum obtained through a diffracting grating is then imaged on the x -dimension of the camera. The complete spectral resonance curve of a full column of sensing spots can be monitored in parallel and in real-time. We demonstrate that data processing is key to reduce the noise and to improve the resolution. We report on the detection of signals with resolution comparable to the one obtained with a classical SPR mono-channel spectroscopic sensor (3.5 × 10 −7 Refractive Index Unit), gaining an order of magnitude compared to SPR imaging sensors. Eventually, we show that short base DNA–DNA hybridizations with concentrations as low as 100 pM can be detected and discriminated in a few tens of minutes following injection by the SPR spectro-imaging system.