Glucose waveguide sensor based on graphene

We described the fabrication of a graphene based bio-chemical sensor integrated with waveguide device. The working principle of the sensor is based on the variation of the local evanescent wave intensity according to the variation of the analyte´s refractive index. Graphene film was transferred onto the field-effect transistor device, and an overlay of polydimethylsiloxane (PDMS) was used as the waveguide. A few microliter drop of analyte was placed on the PDMS waveguide, and the change in the photocurrent through the graphene was monitored. Depending on the concentration of the analyte change, the local evanescent field changed and hence the photo current of the graphene changed. Furthermore, we have evaluated the sensor with the modified graphene-photo detector as well as the surface treated waveguide to enhance the selectivity. We believe that this sensing platform can be used for detection of various bio-analytes and for bio reactions.