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.

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.

[Effect of borate polymer layers on measurement of glucose concentration by SPR].

A new borate polymer PAA-ran-PAAPBA that can specifically adsorb glucose was introduced in the glucose measurement based on surface plasmon resonance, and the high-precision specific detection of glucose concentration was realized. Six layers and twelve layers of borate polymer were respectively bound onto the SPR sensors through the layer-by-layer self-assembly binding method, and the effect of different layers of borate polymer on the glucose surface plasmon resonance measurement was studied. The experiment was conducted in the concentration range of 1-10 mg x dL(-1) (interval delta = 1 mg x dL(-1)), 10-100 mg x dL(-1) (interval delta = 10 mg x dL(-1)), and 100-1 000 mg x dL(-1) (interval delta = 100 mg x dL(-1)), experiment data was fitted by quadric curve and the fitting degree of refractive index difference deltaRU and glucose concentration was obtained. Results showed that the 12-layer-polymer sensor was better than the 6-layer-polymer sensor in the first two smaller ranges, and the measuring result was not significantly affected by layers in the third range, indicating that for the small concentrations increasing polymer layer can dramatically improve the measurement.