Graphene & 2D Materials

Rapid detection of low concentration of specific analytes in small sample volumes is critical in early point-of-care diagnosis. Graphene’s unique electron transport properties and large surface area due to its atom-thick 2D structure makes it a promising candidate for biosensors. Recently, the graphene sensor technology promise to be a vision technology in next generation electronics and sensors - due to graphene’s exceptional electronic properties and aptitude for chemical modification. Graphene based biosensors have been developed, based on chemically functionalised graphene microchannels using wide range of graphene such as epitaxial graphene, screen printed graphene sensors and on CVD graphene. Several different chemical functionalisation methods for graphene have been evaluated and used in sensing applications of graphene, electrochemical and CHEMFET sensors. Direct and indirect (using a modification of an adsorbed layer or polymer film on top of the graphene) functionalisation techniques including diazotisation, aminosilane chemistry and non-covalent functionalisation methods were developed and reviewed. The chemical functionalisation plays a significant role in dictating the sensitivity of the device by improving the attachment of "bioreceptor" molecules, capable of specific and selective detection of target biomarkers. The technology is now being applied to detect blood based biomarkers related to Alzeimers Disease. Changes in the current-voltage characteristics of the graphene sensors are used to detect proteins.