Ultrasensitive graphene field-effect transistor biosensor for rapidly detecting miRNA-208a

MicroRNA-208a (miR208a) is a cardiac-specific miRNA and can provide an earlier prediction for AMI onset than currently used cardiac biomarkers. Graphene field-effect transistor (GFET) biosensor, as the promising candidate for next-generation biosensor, has been demonstrated for real-time detection of a variety of bioactive molecules with ultrasensitivity from nM to fM level. Currently, research on GFET sensors mostly focuses on the properties of the devices themselves, rather than aiming for ultra-sensitive detection based on biochemical substances. In this study, we developed a liquid-gated graphene field-effect transistor-based biosensor for detection of miR208a and designed a portable device to adapt with it for a fast readout of the electronic response, achieving a detection range of 0.01-1 pM, detection limit of 5.3 fM and detection time of 40 minutes. Our work provides a reliable strategy to rapidly and ultrasensitively quantifying miRNA-208a, which also holds great potential to be extended in a wide range of applications of other disease markers and lead to powerful tools for healthcare.