Near-infrared light-assisted dual-modal photoelectrochemical and photo-fuel-cell-driven self-powered biosensor for detection of miRNA-21 in living cancer cells

The advancement of the dual-modal photoelectrochemical (PEC) and photo-fuel-cell-driven self-powered biosensor (PFC-SPB) with the aid of near-infrared light (NIR) irradiation can present a robust sensing strategy for the feasible, sensitive detection of cancer biomarkers in living cancer cells. In this work, a novel NIR-assisted dual-modal PEC and PFC-SPB is proposed for the sensitive inspection of miRNA-21 based on a 2D/2D p-n het-erojunction, which is prepared by the in-situ growth of zinc indium sulfide nanosheets (ZnIn2S4 NSs) over the 2D zinc porphyrin-based metal-organic frameworks using meso-tetra (4-carboxyphenyl) porphyrin as ligand (denoted as ZnIn2S4@Zn-TCPP). Benefiting the integration of the features of ZnIn2S4 and Zn-TCPP, the developed p-n heterojunction demonstrates rich element vacancies, regulated NIR absorption, and improved charge sepa-ration efficiency of the photogenerated electron-hole pairs. Thus, the ZnIn2S4@Zn-TCPP photoelectrode affords the boosted photoelectric conversion efficiency and large output voltage as well as large amounts of anchored complementary DNA strand due to the comprehensive interaction. The constructed dual-modal PEC and PFC-SPB, respectively, exhibit an ultralow limit of detection (LOD) of 0.43 and 0.71 fM toward miRNA-21 within a range of 1 fM to 1 nM, along with the other superior sensing abilities. The PFC-driven self-powered biosensor also shows a great potential in the selective detection of miRNA-21 contained in living cancer cells. The present work provides an NIR-assisted dual-modal biosensing strategy for the efficient analysis of cancer biomarkers in vitro.