Figure 3.

Example of the biosensor with an electrochemical response based on “signal ON”, (A) detection approach using DNA circle for simultaneous detection of miRNA (reproduced with permission from the publisher [60]; (B) scheme of the biosensor design using (a) stand displacement reaction to generates protector output (b) catalytic hairpin assembly to generates H₁/H₂ duplex output and (c) electrochemical signal generation procedure (reproduced with permission of Royal Society of Chemistry) [61].