Graphene chemiresistors as pH sensors: Fabrication and characterization

Keeping a check on pH level is extremely critical for certain physiological events. Ever since its discovery, graphene has rapidly found applications in microelectromechanical systems and nanoelectromechanical systems technology, particularly as sensors. Graphene has been utilized for sensing humidity, hazardous gases, flow, temperature, light, and for very broad applications in biomedical sciences. Recently, some efforts have been made toward developing pH sensors using graphene. In this chapter, we characterize the fabrication and performance of a simple gate-free graphene pH sensor. The simple configuration, miniaturized size, and the integration ability make graphene-based sensors promising candidates for future micro/nanoapplications.