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) ₂ dppz] 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 (V _G ) and hence the modulated channel current (I _DS ) of poly (3,4-ethylenedioxythiophene) doped with poly (styrene sulfonate) (PEDOT:PSS) under specific drain voltage (V _DS ) 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.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)