Graphene based biosensor model for Escherichia coli bacteria detection

As a new nanomaterial, graphene demonstrates great potential as an electrode for biomedical applications in sensing molecules and cells. Thus, development of biosensors based on graphene is gaining much interest due to its exceptional properties such as, large surface-to-volume ratio, high conductivity and high flexibility. In this work a liquid gated graphene field effect transistor based biosensor model is analytically developed for electrical detection of Escherichia coli O157:H7 bacteria. The effect of graphene functionalization on the graphene conductance in the presence of E. coli is investigated. E. coli absorption effects on the graphene surface in the form of conductance variation are considered. Therefore the graphene conductance as a function of E. coli concentration which controls the current-voltage characteristics of biosensors is presented. According to the simulated results, the proposed sensor model can be applied as a powerful tool to predict the biosensor performance