A new method for label-free imaging of biomolecular interactions

A new method for producing label-free high-resolution images of biomolecular binding to the surface of a biosensor is demonstrated. The biosensor incorporates a guided-mode resonance filter that, when illuminated with white light, is designed to reflect only a narrow band of wavelengths where the reflected wavelength is tuned by the adsorption of biological material onto the sensor surface. In this work, an instrument is used to acquire spatial maps of the resonant reflected wavelength in order to produce images of bound biomolecule patterns as applied by a microarray spotter. The biosensor imaging capability is expected to yield applications in pharmaceutical compound screening, genomics, proteomics, and molecular diagnostics, where there is a need to screen large numbers of biochemical interactions against samples using low volumes of reagents.