ABSTRACT
Graphene experiences two-dimensional nanostructures composed of particles of few nanometer thickness. The small thickness of graphene nanosheets endorses its wide use in biosensing applications due to ultra-high conductivity and mechanical strength, high surface area, simple functionalization, and other unique and attractive physiochemical characteristics. Since the last 3-4 years the number of biosensors based on graphene as the primary transducer has been proposed for the detection of various compounds. Graphene-based biosensors are accompanied by high sensitivity, selectivity, fast response time, stability, and low limit of detection. Graphene-based biosensors have the advantage of functionalization with both nonpolar and polar biosensitive materials over the metal-oxide-semiconductors where nonpolar molecules cannot be functionalized effectively. Moreover, through the graphene-based biosensor, direct detection of biomolecules has also been realized with acceptable sensitivity and selectivity. On the basis of high selectivity, sensitivity, simplicity, and potential usability in real-time samples for the graphene-based biosensor, the following chapter provides a brief review of graphene-based biosensors. The chapter includes the fundamental principles involved during the functionalization and the type of electronic sensors based on the graphene material. Examples of biosensors based on graphene include the biosensing of dopamine, glucose, hydrazine, nitric oxide, β-nicotinamide adenine dinucleotide (NADH), and paracetamol. Modication of the graphene biosensor surface with a lipid lm increases the sensitivity of detection. Typical examples of this modication are the biosensing of urea, cholesterol, etc. There has been a growing interest in the use of
novel and attractive functional materials with the emergence of new bioreceptors; therefore, the present time can be considered to witness the birth of a new generation of biosensors which has been realized and adapted.
