Rational Utilization of Photoelectrochemistry of Photosystem II for Self-Powered Photocathodic Detection of MicroRNA in Cells.

The photoanode, photosystem II (PSII)/hierarchical inverse opal (IO) TiO, is coupled to the complementary photocathode, PbS quantum dots (QDs)/DNA probes, which is then integrated into a two-compartment photoelectrochemical (PEC) cell to achieve a self-powered system to enable photocathodic detection of microRNA-10b from HeLa cells. In such a system, all of the PSII catalytic products, i.e., electrons, protons, and O, were rationally utilized and could overcome the general issue of varied O levels in photocathodic detection. The correlation between the target-triggered formation of the DNA complexes and the catalytic reduction of the dissolved O makes possible the steady microRNA-10b detection with good sensitivity and selectivity. This work has unveiled the ability of PSII to construct self-powered detecting devices and shed light on its application in new arenas.