Compact multi-channel high-sensitivity biosensor based on spectroscopy of surface plasmons

We report a compact multi-channel biosensor based on diffraction grating-coupled SPR for the most demanding detection applications in the field or home environments. The sensor utilizes special diffraction grating (referred to as surface plasmon coupler and disperser - SPRCD) for coupling light into the surface plasmon and its simultaneous wavelength dispersion through a different diffraction order. This approach combines most of the optical instrumentation on a single SPR chip produced by stamper hot-embossing technique which is fully compatible with mass production. The sensor consists of a disposable cartridge (SPR chip and microfluidics) and a compact SPR instrument with the footprint which includes optical system of SPR sensor, supporting and data acquisition electronics, microfluidics delivering sample into six independent sensing channels in the cartridge, and temperature stabilization. We demonstrate that the sensor is able to measure changes in the refractive index as low as 2x10-7 refractive index units (RIU) and to detect the binding of antibodies to the antigen-coated sensor surface.