DNA intercalation makes possible superior-gain organic photoelectrochemical transistor detection.

DNA intercalation has increasingly been studied for various scenario implementations due to the diverse functions of DNA/intercalators. Nascent organic photoelectrochemical transistor (OPECT) biosensing taking place in organic electronics and photoelectrochemical bioanalysis represents a promising technological frontier in the arena. In this work, we first devise DNA intercalation-enabled OPECT for miRNA detection with a superior gain up to 17100. Intercalation of [Ru(bpy)2dppz]2+ within the miRNA-initiated hybrid chain reaction (HCR)-derived duplex DNA is realized for producing anodic photocurrent upon light stimulation, causing the corresponding target-dependent alternation in gate voltage (VG) and hence the modulated channel current (IDS) of poly (3,4-ethylenedioxythiophene) doped with poly (styrene sulfonate) (PEDOT:PSS) under specific drain voltage (VDS) for quantitative miRNA-21 analysis, which shows a wide linear relationship and a low detection limit of 5.5 × 10-15 mol L-1. This study features the DNA intercalation-enabled organic electronics with superior gain and is envisaged to attract more attention to explore DNA adducts for innovative bioelectronics and biosensing, given the diverse DNA binders with multiple functions.