Conductivity Measurement of Defect Induced Multilayer Graphene for Escherichia coli Detection

Recently, there has been considerable interest in utilizing graphene for biosensing. Graphene has unique characteristic where the bareness of the graphene allows it to be exposed directly to the aqueous solution. As defect can increase the sensing area and assist the surface's bio-functionalization, hence this paper aims to investigate the biosensing feasibility of defect induced multilayer graphene towards Escherichia coli bacteria detection. Results showed that 10 minutes of incubation time was needed to adsorb E.coli on the graphene surface. In dry measurement, conductivity of the defect induced multilayer graphene decreased but the linearity showed improved range. After the E.coli has been exposed to the defect induced multilayer graphene, the conductivity has been found increased due to the reduction in resistance. This paper showed that the modification on the surface of the graphene can be useful to the sensing application.