Zhenyu Lin

Electrochemiluminescence (ECL) biosensors are widely used for ultrasensitive bioanalysis; however, their practical application is often limited by insufficient interface stability under complex detection conditions. Herein, an integrated hydrogel-AAO membrane (HAM) as a novel composite ion-exchange membrane is developed for constructing stable ECL biosensing interfaces. In the HAM architecture, the agarose hydrogel provides a three-dimensional, biocompatible matrix for antibody immobilization and target recognition, while the highly ordered AAO nanochannels serve as an efficient ion-transport and signal transduction pathway. The composite membrane enables effective coupling between interfacial biorecognition events and ECL signal modulation while physically separating the recognition layer from the ECL reaction region. Using glial fibrillary acidic protein (GFAP), a clinically relevant biomarker for Alzheimer’s disease, as the model analyte, the proposed sensor achieved a detection limit of 191.6 fg/mL with a linear range from 1 pg/mL to 100 ng/mL. The sensor further demonstrated reliable quantification of GFAP in human serum samples, showing good agreement with a commercial ELISA kit. This work establishes the HAM as a versatile composite ion-exchange membrane for ECL biosensing and provides a general design framework for developing stable and sensitive ECL biosensors for clinical analysis.

A glucose oxidase-loaded cobalt-2,3,6,7,10,11-hexahydroxytriphenylene composite (GOx@Co-HHTP) has been designed to be incorporated into a carrageenan matrix to construct a hydrogel-based colorimetric sensor for glucose detection.

Electrochemiluminescence (ECL) is a powerful sensing technique but typically relies on liquid electrolytes and multi-electrode configurations, limiting device miniaturization and integration. Here, we report a solid-state electrochemically driven luminescent sensing platform based on two-electrode junctions comprising an indium tin oxide bottom electrode, a Ru(bpy)32+−TPrA@Nafion active layer (TPrA: tripropylamine), and a soft eutectic gallium−indium (EGaIn) top electrode. Nafion serves as a porous host matrix that immobilizes the luminophore and co-reactant while facilitating analyte uptake, whereas EGaIn provides a simple conformal electrical contact for solid-state operation. Despite the absence of a liquid electrolyte during electrical excitation, the junctions retain key characteristics of classical Ru(bpy)32+ electrochemistry. The luminescence is enhanced by the co-reactant TPrA and quenched by dopamine (DA), enabling quantitative sensing based on modulation of the emission intensity. The platform exhibits a linear response to dopamine over a concentration range of 1.0 × 10−10−1.0 × 10−4 M with a detection limit of 5.1 × 10−11 M, together with excellent reproducibility, selectivity, operational stability, and satisfactory recovery in human serum samples. These results demonstrate that ECL-inspired sensing chemistry can be implemented in a solid-state device architecture, providing a promising strategy for integrated luminescent sensing platforms and miniaturized analytical devices.

Hydrogen sulfide (H2S) serves as an important gasotransmitter implicated in vascular regulation, neuroprotection, and redox homeostasis, and its aberrant fluctuation is closely associated with diverse pathological disorders. Consequently, the development of sensitive and reliable H2S detection methodologies holds considerable significance. Organic photoelectrochemical transistors (OPECTs) integrate photoelectrochemical signal generation with transistor-level amplification, emerging as promising sensing platforms owing to their high sensitivity and low background interference. Nevertheless, the majority of reported OPECT-based sensors rely on the construction of intricate heterojunctions that demand precise energy-level alignment and elaborate material design, thereby elevating system complexity. Herein, an in situ CdS-mediated OPECT sensing platform is innovatively developed for highly sensitive H2S detection and ex vivo analysis of rat brain microdialysates. Specifically, H2S selectively reacts with immobilized Cd2+ to generate n-type semiconductor CdS in situ, which effectively induces and modulates the photovoltage at the gate interface. The modulated photovoltage further regulates the dedoping process of the PEDOT:PSS channel, enabling efficient transduction of interfacial chemical events into amplified current signals. Under optimized conditions, the sensor presents a broad linear response toward H2S ranging from 100 nM to 10.0 mM, with a low detection limit of 51.1 nM. Impressively, by coupling with microdialysis sampling, the platform achieves quantitative analysis of H2S in different regions of rat brain tissue with favorable accuracy and reliability. This work provides a straightforward and efficient strategy for constructing chemically driven photoelectric-transistor coupled amplification sensing systems without complex heterojunction engineering, demonstrating great potential for in situ and in vivo detection of biomolecules in complex biological matrices.

Postoperative delirium (POD) is a severe postoperative neurocognitive complication closely associated with elevated S100-β levels, a key biomarker of neuroinflammation and blood brain barrier disruption. Inspired by the biological cascade of ”molecular recognition, channel opening, ion influx” involved in S100-β-mediated inflammatory, a bioinspired microchannel-based ion current rectification (ICR) sensor was developed for sensitive S100-β detection. In this system, S100-β antibodies were immobilized on the microchannel surface to simulate natural molecular recognition processes. The low isoelectric point of S100-β (~4.7) renders the protein negatively charged under neutral conditions. Specific antigen and antibody recognition increased the interfacial negative charge density of the microchannel, thereby facilitating cation transport and enhancing the rectification response under an applied electric field. This process mimics the biological processes of channel opening and ion influx in living systems. The proposed sensor exhibited reliable analytical performance and was successfully applied to clinical serum analysis, showing good agreement with enzyme-linked immunosorbent assay. This work provides a promising strategy for POD-related biomarker analysis and broadens the application of bioinspired microchannel-based ICR sensors in clinical diagnostics and bioanalytical sensing.

To elucidate the synergistic effects of storage temperature and packaging on N-nitrosodimethylamine (NDMA) and its precursors dimethylamine (DMA) and trimethylamine N-oxide (TMAO) in roasted Alaska pollock fillets, two storage experiments were conducted. In Experiment I, commercially packaged fillets were stored at −20, 4, 10, 20, and 30 °C for 310 d. A two-way factorial ANOVA revealed a significant temperature × time interaction (F(24, 70) = 39.386, p < 0.001, partial η² = 0.931). NDMA formation was delayed until day 172 at −20 °C; however, the 4, 10, and 20 °C groups exceeded the 4 μg/kg limit by day 263, with the 20 °C group peaking at day 263 (4.26 μg/kg) before declining to 3.73 μg/kg by day 310. In Experiment II, a three-way factorial ANOVA was applied to samples stored under oxygen-absorber or vacuum packaging at refrigerated (4 °C) or ambient (22 °C) temperature for 270 days. The temperature × packaging × time interaction was significant for NDMA, DMA, and TMAO (p < 0.001). The partial η² for NDMA (0.933) was markedly larger than for DMA (0.540) and TMAO (0.607), indicating stronger combined effects on NDMA. The main effect of temperature on DMA was dominant (partial η² = 0.994), whereas NDMA formation depended strongly on both temperature and packaging. During the 270-day storage, all refrigerated groups remained below the 4 μg/kg limit throughout; however, the ambient vacuum-packaged (BCZ) group transiently exceeded the limit (reaching 4.21 μg/kg on day 60) and subsequently fluctuated near the limit. These findings provide a scientific basis for designing safer storage and packaging strategies for such dried aquatic products.

A surface-enhanced Raman scattering (SERS) detection method based on hydrogel chips was developed for the label-free, high-throughput, simultaneous screening and determination of three adenine-type cytokinins, including 6-benzyladenine (6-BA), kinetin (KT) and N6-isopentenyladenine (iP) in agricultural products. After systematic optimization, the characteristic Raman peaks of the three analytes were clearly identified, enabling simultaneous multi-component recognition in a single spectrum. Under optimal conditions, the characteristic peak intensities showed good semi-log linear relationships with concentrations, and the limits of detection were about 0.5 ng/mL, 0.5 ng/mL, and 3 ng/mL for 6-BA, KT, and iP, respectively. This method allows simultaneous qualitative and quantitative analysis of multiple components in one sample with high sensitivity and strong anti-matrix interference capacity, providing an efficient strategy for the high-throughput supervision of cytokinin residues.