Metal-organic polymer enables efficient organic photoelectrochemical transistor biosensing.

The field of organic photoelectrochemical transistor (OPECT) is newly emerged, with increasing efforts attempting to utilize its properties in biological sensing. Advanced materials with new physicochemical properties have proven important to this end. Herein, we report a metal-organic polymers-gated OPECT biosensing exemplified by CuⅠ-arylacetylide polymers (CuAs)-modulated poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel. Both the photoelectrochemical properties and gating capability of CuAs are explored and optimized for high-efficacy photogating. Morever, based on its inherent structure, the specific reaction between CuAs and sulfur ions (S2-) is revealed and S2--mediated microRNA-21 detection is realized by linking with nucleic acid amplification and alkaline phosphatase catalytic chemistry. This work introduces metal-organic polymers as gating materials for OPECT biosensing.

Chemical Redox Cycling in an Organic Photoelectrochemical Transistor: Toward Dual Chemical and Electronic Amplification for Bioanalysis.

The organic photoelectrochemical transistor (OPECT) has been proven to be a promising platform to study the rich light-matter-bio interplay toward advanced biomolecular detection, yet current OPECT is highly restrained to its intrinsic electronic amplification. Herein, this work first combines chemical amplification with electronic amplification in OPECT for dual-amplified bioanalytics with high current gain, which is exemplified by human immunoglobulin G (HIgG)-dependent sandwich immunorecognition and subsequent alkaline phosphatase (ALP)-mediated chemical redox cycling (CRC) on a metal-organic framework (MOF)-derived BiVO4/WO3 gate. The target-dependent redox cycling of ascorbic acid (AA) acting as an effective electron donor could lead to an amplified modulation against the polymer channel, as indicated by the channel current. The as-developed bioanalysis could achieve sensitive HIgG detection with a good analytical performance. This work features the dual chemical and electronic amplification for OPECT bioanalysis and is expected to stimulate further interest in the design of CRC-assisted OPECT bioassays.