Highly sensitive solution-gated graphene transistors for label-free DNA detection

Highly sensitive and low-cost DNA detection are in great desire owing to the significant role of DNA molecules in detecting genetic damage and errors for the diagnosis and treatment of multiple diseases. Traditional detections of DNA mainly rely on large-scale instrument, which requires the complicated detection process and high cost. Solution-gated electrochemical transistors are widely studied due to high sensitivity and low cost. Here, we exploit a graphene electrochemical transistor for the efficient and sensitive DNA detection. The probe DNA is modified on the gate electrode to detect the target DNA molecules. A novel method is introduced to modify the gate electrode with the probe DNA to detect the different concentration of target DNA. Herein, in comparison with previous reported methods, our DNA sensors show a good limit of detection in the range of 1 fM - 5 μM. The highly sensitive and selective validate the developed DNA sensor as a promising tool for routine use.