Fabrication of a biosensor with embedded waveguides for sensing in microchannels

The fabrication and testing of a novel waveguide based biosensor for sensing in microchannels is presented. Unlike evanescent wave sensing, which has large intrinsic losses, an absorption based sensing scheme was introduced. The fabricated waveguide sensor has excellent transparency in the UV-Vis region of the spectra and is able to perform simultaneous detection of multiple analytes in microchannels. The optical interconnection to the device was achieved using self-aligned V-grooves etched on the silicon wafer using KOH etching. The fabricated device has applications in micro total analysis systems for measuring various analytes in the microchannels, tissue engineering for continuous measurement of the oxygen in the artificial scaffolds, and fluorescence-based measurement by attaching fluorescent dyes to the waveguide end face in the microchannel.