Abstract
Multispectral and hyperspectral imaging have been extensively applied in various imaging domains, where spectral channels with narrow bandwidths provide detailed information for optical signal analysis. The integration of multi-channel filter arrays with image sensors is essential for multispectral detection. To extend this capability to cameras without integrated filters, a dual-band spectral filter array (DSFA) combined with a telecentric lens was employed with a monochrome camera for real-time surface plasmon resonance imaging (SPRi). Placement of the DSFA in front of a broadband light source generated spatially modulated excitation signals incident on a gold-coated periodic silicon nanostructure serving as a surface plasmon resonance (SPR) chip. A pixel-shift-based demosaicing method enabled the separation of checkerboard-like images into two spectral bands corresponding to the filters of the DSFA, facilitating γ-based spectral contrast response analysis. This optical configuration successfully demonstrated dynamic monitoring of the interaction between anti-BSA and immobilized BSA on the chip. Compared with wavelength-shift analysis, γ-based analysis improved the refractive index detection limit by nearly two orders of magnitude, enabling highly sensitive monitoring of biomolecular interactions. The DSFA-based SPRi platform provides a flexible, highly integrable, and label-free solution for quantitative analysis of biomolecular interactions.