A biosensor is an analytical device, used for the detection of a chemical substance, that combines a biological component with a physicochemical detector. The sensitive biological element, e.g. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc., is a biologically derived material or biomimetic component that interacts with, binds with, or recognizes the analyte under study. The biologically sensitive elements can also be created by biological engineering. The high surface-to-volume ratio of graphene and graphene-like structures provide sufficient loading of the required ligand onto the graphene layers. Besides, the excellent conductivity and small bandgap of graphene-like materials make them useful for sensitive electrical and electrochemical detection graphene-like materials are suitable for use as fluorescence and plasmonic sensor due to their tunable optical properties. In general terms, graphene-based sensors consist of a receptor, such as an antibody, single-stranded DNA, or enzyme that can be combined with the target ions, molecules, nucleic acids, or even whole cells or microorganisms. The graphene-based nanomaterials also serve as the transducer to convert chemical information regarding the interactions between the receptor and the target molecules into a measurable signal.
