A triple-helix molecular switch photoelectrochemical biosensor for ultrasensitive microRNA detection based on position-controllable CdS//CdTe signal enhancement and switching.

Herein, a triple-helix molecular switch photoelectrochemical (PEC) biosensor is developed for ultrasensitive and selective detection of microRNA based on position-controllable CdS//CdTe signal enhancement and switching accompanying the signal amplification of a three-dimensional DNA walking machine. The developed PEC biosensor exhibits excellent analytical performance for microRNA-141 detection with a wide linear range from 5 aM to 100 fM, a low detection limit of 1.3 aM and outstanding selectivity.