Photo-driven self-powered biosensors for ultrasensitive microRNA detection based on metal-organic framework-controlled release behavior

We developed a “signal-on” self-powered biosensing strategy by taking full advantage of both photoelectrochemical biofuel cells (PBFCs) and metal-organic framework (MOF)-controlled release behavior for ultrasensitive microRNA assay. PBFCs-based self-powered sensors not only have the unique characteristics of no need for external power sources, simple fabrication process, miniature size, good anti-interference ability and low cost. Furthermore, based on the target microRNA-induced release of the electron donor ascorbic acid and the high catalytic ability of biocathode on oxygen reduction reaction, photo-driven self-powered biosensors for ultrasensitive microRNA detection were successfully realized. The as-proposed signal-on biosensor not only provides a simple and effective strategy, but also possesses the merits of wide dynamic concentration response range and high sensitivity for microRNA detection, with a limit of detection down to 0.16 fM.