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Single-cell interrogation with the solid-state nanoprobes enables understanding of the linkage between cellular behavior and heterogeneity. Herein, inspired by the charge property of the organic molecular probe (OMP), a generic ionic current rectification (ICR) single-cell methodology is established, exemplified by subcellular detection of glutathione (GSH) with high selectivity, sensitivity, and recyclability. The as-developed nanosensor can transduce the subcellular OMP-GSH interaction via a sensitive ionic response, which stems from the superior specificity of OMP and its essential charge property. In addition, the nanosensor exhibits good reversibility, since the subsequent tandem reaction after the recognition can well recover the sensing surface. Given the diverse structures and tailorable charge properties of OMP, this work underpins a new and general method of OMP-based ICR single-cell analysis.

Nature makes use of molecular charges to operate specific biological synthesis and reactions. Targeting advanced opto-bioelectronic sensors, organic photoelectrochemical transistors (OPECTs), taking advantage of the light fuel substituting an external gate potential, is now debuting and expected to serve as a universal platform for studying the rich light-biomatter interplay for new bioanalytics. Given the ubiquity of charged biomolecules in nature, molecular charge manipulation should underpin a generic route for innovative OPECT regulation and operation, which nevertheless has remained unachieved. Herein, this work manifests the biological tuning of surface charge toward the OPECT biosensor, which was exemplified by a light-sensitive CdS quantum dot (QD) gate electrode interfaced by a smart DNA superstructure with adenosine triphosphate (ATP) responsiveness. Highly negative-charged supramolecular DNA concatemers were self-assembled via sequential hybridization, and the ATP-triggered disassembly of the DNA concatemers would cause a tandem change of the effective gate voltage and transfer characteristics with significantly improved resolution. The present opto-bioelectronic device translates the events of charged molecules into amplified electrical signals and outlines a generic format for the future exploitation of rich biological tunability and light-biomatter interplay for innovative bioanalytics and beyond.

This work reports the elegant bridging of enzymatic generation of electron donor with photogenerated hole-induced chemical redox cycling amplification (RCA) for innovative photoelectrochemical (PEC) immunoassay, by the aid of a heterojunction photoelectrode with split-type strategy. Specifically, the system was exemplified by the alkaline phosphatase (ALP) catalytic generation of ascorbic acid (AA), the redox cycling of AA by tris (2-carboxyethyl) phosphine (TCEP) as reductant, and the use of a novel Bi2S3/Bi2Sn2O7 heterojunction and myoglobin (Myo) as the photoelectrode and the target, respectively. After the immunoreaction and ALP-induced production of AA, the subsequent oxidation of AA by the photogenerated holes of the Bi2S3/Bi2Sn2O7 heterojunction could be cycled via the regeneration of AA by TCEP from the oxidized product of dehydroascorbic acid, leading to easy signal amplification for the sensitive immunoassay of Myo in real samples. It is believed that this work provided a basis for further desig...

This work reports the elegant bridging of enzymatic generation of electron donor with photogenerated hole-induced chemical redox cycling amplification (RCA) for innovative photoelectrochemical (PEC) immunoassay, by the aid of a heterojunction photoelectrode with split-type strategy. Specifically, the system was exemplified by the alkaline phosphatase (ALP) catalytic generation of ascorbic acid (AA), the redox cycling of AA by tris (2-carboxyethyl) phosphine (TCEP) as reductant, and the use of a novel Bi