Label-free analysis of thrombin or Hg²⁺ ions by nucleic acid-functionalized graphene oxide matrices assembled on field-effect transistors

Graphene oxide (GO) is deposited onto the Al₂O₃ gates of field-effect transistor devices to yield a functional matrix for the sensing of thrombin or Hg²⁺ ions. The deposition of an aptamer subunit against thrombin or a tailored nucleic acid with appropriate T mismatches on the GO, yield active surfaces for the analysis of thrombin or Hg²⁺ ions. The desorption of the aptamer-subunit from GO, through the formation of the aptamer-thrombin complex, or the desorption of the T-Hg²⁺-T-bridged duplex DNA alter the gate potential, thus providing a signal for the sensing events.