Biosensors based on DNA-Functionalized Graphene

Since its discovery, graphene has been used for sensing applications due to its outstanding electrical properties and biocompatibility. Here, we demonstrate the capabilities of~field effect transistors (FETs)~based on~CVD-grown graphene functionalized with commercially obtained DNA oligomers and~aptamers~for detection of various biomolecular targets (e.g., complementary DNA and small molecule drug targets). Graphene~FETs were created with a scalable photolithography process that produces arrays consisting of~50-100~FETs with a layout~suitable for multiplexed detection of four molecular targets. FETs were characterized via AFM to confirm the presence of the aptamer.~From the measured electrical characteristics, it was determined that binding of molecular targets by the DNA chemical recognition element led to a reproducible, concentration-dependent shift in the Dirac voltage. This biosensor class is potentially suitable for applications in drug~detection. This work is funded by NIH through the Center for AIDS Research at the University of Pennsylvania.