Label-free detection of DNA hybridization using transistors based on CVD grown graphene

The high transconductance and low noise of graphene-based field-effect transistors based on large-area monolayer graphene produced by chemical vapor deposition are used for label-free electrical detection of DNA hybridization. The gate materials, buffer concentration and surface condition of graphene have been optimized to achieve the DNA detection sensitivity as low as 1pM (10−12M), which is more sensitive than the existing report based on few-layer graphene. The graphene films obtained using conventional PMMA-assisted transfer technique exhibits PMMA residues, which degrade the sensing performance of graphene. We have demonstrated that the sensing performance of the graphene samples prepared by gold-transfer is largely enhanced (by 125%). [Display omitted] ► Single-layer graphene FETs show higher sensitivity for DNA detection than few-layer graphene. ► The detection limit of single-layer graphene devices can achieve as low as 1pM (10−12M). ► The sensing performance of graphene FETs prepared by cleaner transfer technique is 125% enhanced.