Benefiting from the low chance of circuit leakage and the sufficient driving forces, the entropy-driven DNA amplifier has attracted great attention in constructing new fluorescent biosensors to operate in live specimen. But unfortunately, this promising signal amplification means still confront with some inevitable defects such as poor accuracy, inferior bio-stability and unsatisfactory biological uptake efficiency. To deal with these challenges, we propose here a series of rewarding sensing designs. First, an exceptional light-gated manner is integrated by embedding the sensing elements with a photocleavage-linker, under which the target specific recognition is capable of being initiated in a faultless control mode under a light irradiation. Then, dual DNA tetrahedrons are employed to anchor the linear DNA probes on their endpoints to significantly improve the enzyme resistance in complex biological medium. After that, a two-dimensional nanomaterial (MnO2 nanosheets) that can be efficiently reduced by biothiols is selected as an auxiliary nanovector to promote the endocytosis. By virtue of these efforts, this special biosensor is endowed with a good assay performance towards an underlying lung cancer related biomarker (microRNA-196a), wherein the sensitivity is as low as 3.2 pM and the specificity owns an identification ability for single-base mismatching. More importantly, our method can be utilized as a highperformance imaging toolbox for reliably detecting the target in live cancer/normal cells and bodies, offering a broad application prospect for cancer diagnosis.
