Chemiresistive and resistive switching semiconductor based sensor for biomolecule detection

Recently, chemiresistive semiconductor, which varies its resistance or conductance status based on chemical phenomena at its surface, has been developed as a sensor device for biomolecule detection. Particularly, graphene has been one of the best example for the chemiresistive semiconductors, even for resistive switching semiconductors. In addition, the graphene is two-dimensional (2D) carbon structure having a large surface area, where significant biosensing applications have been continuously reported. In this study, we demonstrated reduced graphene oxide (rGO) biosensor structure for a stress hormone, i.e. cortisol, sensing. The device structure was stepwise self-assembly monolayers (SAMs) stacked by reduced graphene oxide between source and drain. Then, cortisol monoclonal antibody (c-Mab) was chemically tethered on reduced graphene oxide layer for the cortisol detection by its specific antigen-antibody binding. The current versus voltage (I-V) curve exhibited resistance changes and resistive switching I-V behaviors as a sensing mechanism, which demonstrated a unique possibility of rGO semiconductor based sensor. Also, chemiresistance change in the forms of resistance ratio was calibrated in terms of sensing cortisol concentration as shown in Figure 1. Please click Additional Files below to see the full abstract