Graphene-Based Electrodes for Electrochemical Sensors

Graphene-based electrodes are potential candidates and significantly participate in electrochemical reactions, providing high reactivity and selectivity. Their reaction assists in transferring electrons between the electrode and reactants and facilitates an intermediate chemical transformation described by an overall half-cell reaction. Graphene-based materials with metal/metal oxides and sulphides have been extensively applied for the fabrication of highly sensitive electrochemical sensors. They have excellent physical, chemical, electrical, and surface properties and are extensively used in the development of sensors. Graphene-based nanomaterials have also been successfully utilised for clinical diagnosis, disease treatment, and many biocompatible sensors. This chapter mainly focuses on the sensing mechanism of graphene-based electrochemical sensors via different approaches of potentiometry, amperometry/voltammetry, and conductometry. The electronic properties of graphenebased nanomaterials have been briefly discussed and are responsible for their outstanding sensing ability. We have also explored different forms of graphene and its derivatives with their properties and applicability in fabricating electrochemical sensors to better influence graphene for superior functioning. There is also a discussion about the general reactions (reduction/oxidation) involved within analytes and graphene materials in fabricating electrochemical sensors. Finally, a conclusion was drawn on the basis of the usage of graphene-based materials in electrochemical sensors for future electrocatalytic applications in various fields of biomedical diagnosis, environmental monitoring, food sensors, and hazardous fumes.

Keywords: Amperometric, Conductometric, Electrocatalyst, Electrochemical, Impedance, Nyquist Plot, Potentiometric, Sensors, Voltametric.