Development of a scanning surface plasmon microscope based on white light for analysis of a wide range of protein arrays

We present a white light-based self-developed scanning surface plasmon microscope (SPM) for high spatial resolution analysis of a wide range of protein arrays. The image contrast mechanism and an optimal detection wavelength for surface plasmon resonance (SPR) imaging experiments were investigated with Fresnelʹs equations. Fluctuation of the SPR image intensity was below ±1.3% for the pure Au surface. The spatial resolution of the scanning SPM was approximately 53 μm × 54 μm. The performance of the scanning SPM was evaluated by the rapid analysis of immunoreactions of C-reactive protein and haptoglobin on protein arrays, and the results were consistent with those obtained by the previously used spectral SPR biosensor. Then, the scanning SPM was successfully applied to the analysis of a wide range of protein arrays with various concentrations of GST-PBD. These results suggest that scanning SPM can be used as a useful platform for high-throughput analysis of a wide range of protein arrays in a label-free format.