Abstract: A microdevice for monitoring a target analyte is provided. The microdevice can include a field effect transistor comprising a substrate, a gate electrode, and a microfluidic channel including graphene. The microfluidic channel can be formed between drain electrodes and source electrodes on the substrate. The microdevice can also include at least one aptamer functionalized on a surface of the graphene. The at least one aptamer can be adapted for binding to the target analyte. Binding of the target analyte to the at least one aptamer can alter the conductance of the graphene.