The low temperature electrocatalysis of CO2 to CO typically requires purified CO2, adding complexity, cost, and energy penalties due to the need for separate CO2 capture and purification processes. Electrochemical reactive capture (e-RCC) is emerging as a simplification of the process. The method combines CO2 capture with amines to form ammonium carbamates which are then reduced to produce CO and H2. Heterometallic polyoxometalate catalysts were evaluated for e-RCC by cyclic voltammetry showing that [SiCu2IIGaIII(H2O)3W9O37]9- had the lowest overpotential and highest turnover frequency. A combination of cyclic voltammetry and controlled potential electrolysis and transport measurements of carbamates through Nafion membranes revealed that commonly used small-molecule carbamates easily traversed membranes and were oxidized at the anode to CO and CO2. To avoid anodic amine oxidation, polyammonium carbamates were prepared, and the method provides an efficient way to convert CO2 captured into valuable carbon monoxide. Controlled potential electrolysis confirmed that [SiCu2IIGaIII(H2O)3W9O37]9- reduced polyammonium carbamate at a negative potential of -1 V vs. Ag/AgCl, forming CO and H2, while other polyoxometalate catalysts yield CO and H2 at more negative potentials of -1.3 V. This research combines the use of polyoxometalates for electrocatalysts for e-RCC and provides a potential pathway to avoid detrimental amine/carbamate anodic oxidation.

This study investigated how electrode design and electrical conditions influence iontophoretic transdermal drug delivery. A low-resistance silver electrode (Ag*) was developed to reduce interfacial resistance and improve the delivery of lidocaine hydrochloride (LID·HCl). In vitro permeation experiments were conducted using pig ear skin mounted on diffusion cells. Iontophoresis was applied under constant current, constant voltage, and battery-powered conditions. Ag* and conventional Ag electrodes were compared as anodes, with an Ag/AgCl cathode. Drug permeation and current profiles were measured over 8 h. Under constant current conditions, LID·HCl permeation through skin increased linearly with current density (r = 0.993). Enhanced permeation was also observed under constant voltage and battery-driven systems. The Ag* electrode produced higher current and greater drug permeation than the conventional Ag electrode at the same voltage due to its microstructured surface, which increased effective surface area and reduced charge-transfer resistance. Skin permeation was governed by current intensity. The Ag* electrode enabled efficient drug delivery even with simple battery systems, suggesting its potential for use in wearable transdermal delivery devices.

Wearable electronics, particularly dry epidermal electrodes, provide human-connected interfaces for recording biopotential signals. However, their practical utility is often hindered by their limited operational longevity and the resulting environmental burden of electronic waste, as most conventional electrodes are discarded after a single use because of performance degradation. Herein, a reusable, soft, and conductive epidermal electrode is reported, fabricated through the precise incorporation of functional additives. By intentionally modulating the polymer chain architecture, a homogeneous composite is developed that exhibits exceptional flexibility, high conductivity (~100 S/cm), softness (~649 kPa), and stretchability (~234%). This molecular-level design promotes strong intermolecular interactions at the skin-electrode interface, facilitating persistent adhesion and conformability to challenging surfaces, including wet, wrinkled, and stretched skin. These properties enable reliable electrocardiography acquisition through 50 repeated attachment and detachment cycles, over which a commercial Ag/AgCl gel electrode became unmeasurable after 20. The applicability of the electrode to human-machine interfaces is further demonstrated by capturing clear electromyography signals of muscle activity during a rock-paper-scissors game. This low-modulus electrode platform offers a route towards repeated-use wearable healthcare systems and soft-robotics applications, with the potential to reduce the waste associated with single-use electrodes.

To address the core challenge of balancing electrical conductivity, mechanical toughness, and biocompatibility in flexible bioelectronic electrodes, this study proposes a PAM molecular bridge directional coupling strategy. We in situ fabricated a CCNFs/PEDOT: PSS-co-PAM (PSM) composite hydrogel, with linear CMC as a control. Via multiscale characterization and molecular dynamics (MD) simulations, we clarified key structure-property links. PAM segments act as "molecular bridges," conferring flexibility and biocompatibility, while their amide groups form high-density hydrogen bonds with CCNF's ordered carboxyl groups. This anchors the 3D rigid CCNF framework to PEDOT: PSS chains, thereby optimizing stress transfer and charge transport. In contrast, CMC's linear structure and ether-linked carboxyl groups yield weak interfacial interactions. MD simulations confirmed the CCPSM system has 1.6× more hydrogen bonds, 3.36× higher interaction energy, and 63.4% lower water diffusion vs. CMC. CCPSM-5 exhibits 2.16 S/m conductivity, 5.7× higher toughness (3.165 MJ·m[-3]), 1.2× higher elongation (746%), plus excellent adhesion, anti-swelling, and dynamic electrical stability on glass and dry/wet skin. As a bioelectrode, it outperforms commercial Ag/AgCl in EMG/ECG signal fidelity and RMS, enabling precise multi-joint motion monitoring. This work resolves the conductivity-mechanical trade-off by leveraging CCNF's 3D reinforcement and interfacial coupling, offering a novel design paradigm for high-performance flexible bioelectronics.

The monitoring of synthetic antioxidants in food products is essential for quality and consumer safety. In this work, we present the very first electrochemical sensing application of mono-Boc-ethylenediamine-functionalized graphene oxide (GO-EnBoc) nanosheets for the sensitive determination of tert-butylhydroquinone (TBHQ), a widely used food preservative. GO-EnBoc was synthesized by covalent intercalation of mono-Boc-ethylenediamine into the layers of graphene oxide and characterized by various techniques. XRD analysis revealed a significant increase in the interlayer spacing from 0.93 nm to 1.20 nm, indicating successful intercalation, and FTIR spectra confirmed the introduction of nitrogen-containing functional groups. Morphological investigations showed a wrinkled, ultrathin layered structure with improved surface accessibility and electron transfer properties. We investigated the electrochemical sensing performance of GO-EnBoc modified glassy carbon electrodes using differential pulse voltammetry (DPV). At around 0.33 V (vs. Ag/AgCl), the modified electrode presented a well-defined TBHQ oxidation peak and a linear response in the concentration range of 0.1-130 µM with a correlation coefficient of 0.99. The sensor exhibited a low limit of detection (LOD) of 95 nM and a limit of quantification (LOQ) of 0.31 µM. Good repeatability (RSD = 2.1%) and reproducibility (RSD = 3.4%) were obtained. The practical applicability of the sensor was confirmed in chips, popcorn, and edible oil samples with a recovery of 92% to 102%. These findings demonstrate GO-EnBoc as an attractive platform for rapid, reliable, and portable electrochemical monitoring of synthetic antioxidants in complex food matrices.

Arsenic (As) is a toxic metalloid that affects over 100 million people worldwide. Bioelectrochemical systems (BESs) offer a new opportunity to catalyze the biological oxidation of arsenite to arsenate, decreasing toxicity and improving subsequent physicochemical separation steps. However, research on arsenic-related electrochemically active microorganisms (As-EAMs) remains limited. This study electrochemically enriched As-EAMs from sediments of a hydrothermal source in northern Chile using a three-electrode cell. Chronoamperometry was run for 116 days at a poised potential of +0.3V (vs. Ag/AgCl) and under open-circuit potential (O.C.P.). Bacterial colonization over carbon cloth electrodes was examined by scanning electron microscopy and flow cytometry, while microbial communities were characterized via 16S rRNA gene sequencing (Illumina MiSeq). Our results indicated that Rhodococcus sp. was the most abundant genus in both conditions, representing over 90% of the relative abundance. Despite this shared dominance, the poised-potential assay showed 27% and 39% dissimilarity in attached and planktonic communities, respectively, relative to O.C.P. This compositional difference was associated with a higher As(III) oxidation rate: 20% under poised potential versus 5.5% for O.C.P. and less than 3.7% for abiotic controls (p < 0.05). This research improves our understanding of As-EAMs and supports the development of novel electro-biotransformation strategies.

Monkeypox (Mpox), a viral zoonotic disease caused by the monkeypox virus (MPXV) remains a significant global public health concern. Current laboratory diagnostics are limited by high biosafety requirements and complex workflows, preventing point-of-care (POC) use. To address these limitations, a disposable, label-free electrochemical immunosensor was developed to detect the MPXV A29 glycoprotein, a highly immunogenic and diagnostically relevant protein. Shape-controlled, reproducible, hollow porous gold sub-microcubes (HPGCs) were synthesized using AgCl as a sacrificial template. The screen-printed carbon electrode was functionalized with poly-l-cysteine and HPGCs bearing a surface-confined 6-(ferrocenyl)hexanethiol probe and antibody for selective antigen binding. Antigen binding attenuates the ferrocene electrochemistry, investigated by voltammetry and impedance spectroscopy. The high surface-to-volume ratio and electrocatalytically active centers of HPGCs enable high loading of ferrocene and antibodies. The surface-confined signaling probe eliminates the need for an external signaling probe, offering a portable, reagent-free POC testing. The sensor offers a wide linear range (0.1-3200 ng/mL), low detection limit (0.1 ng/mL), excellent selectivity against non-target proteins, high reproducibility (RSD = 3.73%), and strong recovery in spiked serum with minimal matrix effects. These findings demonstrate a robust, sensitive, and user-friendly diagnostic strategy for field-based Mpox surveillance in resource-limited settings.

Physiological signal acquisition is essential for medical diagnostics and human-machine interfaces. Motion artifacts and sweat-induced instability present persistent challenges for conventional electrodes, fundamentally limiting their reliability in dynamic or long-term use. Here, we report a Janus hydrogel electrode that combines high electrical conductivity (3 × 10[4] S·m[-1]), strong interfacial adhesion to copper surfaces (2079 J·m[-2]), and low skin-electrode impedance (∼300 Ω). Distinct from conventional Ag/AgCl electrodes, hydrogel electrode uniquely combines hydrophobic protection, high-strain impedance insensitivity (250%) and rapid self-healing, achieving interference-resistant physiological signal monitoring even under vibration and moisture interferences. Notably, coupling with advanced Transformer algorithms optimized for temporal sequence analysis, the electrodes delivered 97.02% gesture recognition accuracy. This system harnesses these gestures to generate robust and intuitive command inputs, paving the way for potential rehabilitation applications, where future clinical validation is required. This work introduces a multifunctional, biocompatible electrode platform that couples reliable physiological monitoring with AI-powered rehabilitation assessment, opening new avenues for next-generation intelligent wearable bioelectronics.

Electrosorption is a promising strategy for removing ionic organic pollutants and in-situ adsorbent regeneration; however, a lack of mechanistic understanding hinders its broader application. This study systematically investigates the potential-dependent adsorption of 21 structurally diverse persistent, mobile, and potentially toxic compounds (PMs/PMTs), spanning cationic, anionic, zwitterionic, and neutral species with and without aromatic moieties. Experiments were conducted at trace concentrations in realistic tap water matrix using activated carbon felt electrodes with tailored surface chemistries across a potential range of -1 V to +1 V (vs. Ag/AgCl). Results demonstrate that electrosorption is governed by superimposed electrostatic and non-electrostatic interactions, strongly modulated by molecular structure. Non-aromatic ions exhibit electrostatically dominated behavior, following bell-shaped curves with maxima at moderate opposite-charge potentials, with adsorption coefficients (Kd) varying by up to 5 log units. In contrast, aromatic compounds show enhanced adsorption under cathodic polarization regardless of charge, indicating potential-induced strengthening of π-π interactions. Oxygen-rich surface chemistries attenuate these effects, limiting Kd variations to ≤ 2 orders of magnitude. Desorption hysteresis in aromatic species identifies a critical boundary for electrode regenerability, suggesting tailored designs for aromatic vs. non-aromatic fractions. This work provides a foundation for the predictive design of electrosorption processes in realistic water treatment scenarios.

Indium sulfide thin films play a crucial role in photoelectrochemical (PEC) water splitting, offering promising strategies to mitigate energy shortages and global warming. In this study, indium sulfide thin films were synthesized via a hydrothermal method, and the effects of sulfur precursors-l-cysteine (LC) and l-cysteine hydrochloride (LCHCl)-along with hydrothermal temperature ramp rates (3 and 10 °C min[-1]) on their crystallographic orientation, morphology, and thickness were investigated. The findings revealed that films synthesized with LC predominantly exhibited the (440) facet, while those synthesized with LCHCl had the (311) facet. Additionally, films produced at 3 °C min[-1] were thicker than those synthesized at 10 °C min[-1]. The film (LC-IS-10) synthesized at 10 °C min[-1] using LC achieved a photocurrent density of 3.7 mA cm[-2] at -0.2 V vs. Ag/AgCl, which outperformed that of LCHCl-synthesized film (LCHCl-IS-10) at the same heating rate (2.6 mA cm[-2]) and those of the films synthesized at 3 °C min[-1] (LC-IS-3: 0.7 mA cm[-2] and LCHCl-IS-3: 2 mA cm[-2]). 2-Hour photocurrent stability assessments indicated that LC-synthesized films (LC-IS-3: 1 mA cm[-2], LC-IS-10: 670 μA cm[-2]) exhibited superior stability to the LCHCl-synthesized films (LCHCl-IS-10: 90 μA cm[-2], LCHCl-IS-3: 33 μA cm[-2]). This improved stability was attributed to their (440) facet, which was structurally more compact and symmetric and exhibited reduced sulfur exposure than the less ordered (311) facet. Although the LC-IS-3 film had the lowest photocurrent density, it showed enhanced stability, owing to the thickness alteration caused by the oxidation of surface S[2-] species. This research provides insights for optimizing material design in PEC water-splitting applications, advancing sustainable energy solutions.

Bioelectrochemistry enables uranium recovery from uranium-contaminated water. Within microbial electrolysis cells (MECs), electroactive biofilm growth is critical, but the impact of electrode potential on biofilm structure and function remains unknown. This study explored variations in micro-structure, extracellular electron transfer, and uranium recovery of Shewanella oneidensis MR-1 biofilms cultivated under different potential shocks from -0.2 to 0.6 V (vs Ag/AgCl) in MECs at -0.2 V. Across this range, uranium recovery exhibited a clear non-monotonic trend, peaking at 0.2 V and exhibiting the most unreliable performance at 0.6 V. At 0.2 V (low potential, LP), the biofilm electrode exhibited 99.72 % uranium recovery with 42.19 % U(IV) reduction. Additionally, transmission electron microscopy revealed needle-like mineral within the inner extracellular polymeric substances (EPS), attributed to moderate c‑type cytochrome (c-Cyts) density (104.89 % of open circuit potential, OCP), suitable charge transfer resistance (Rct, 68.34 % of OCP), and a dense EPS network (bulk density 138.07 % of OCP). At 0.6 V, the biofilm exhibited higher electrochemical activity (c-Cyts 113.15 % and Rct 48.41 % of OCP), but poorer structural stability (EPS bulk density 101.38 % of OCP), causing fluctuating recovery (99.39 % to 94.10 %) and a lower U(IV) proportion (33.90 %). These results indicate that balancing biofilm activity and structural stability is essential for efficient and sustainable recovery of uranium. The LP biofilm electrode achieved 98.09 % uranium recovery with a surface distribution coefficient (Kd,s) of 1.414 L/cm[2] in real mining groundwater. This finding presents a balance model linking biofilm electrode activity and stability, highlighting the necessity of regulating cultivation potential shock.

The development of a green methodology for the synthesis of silver/zinc/carboxymethyl cellulose (Ag/ZnO/CMC) nanocomposites using cinnamon extract as a reducing and stabilizing agent is reported herein. The innovation aspect of this research is the incorporation of biogenic Ag and Zn nanoparticles into the biodegradable CMC polymer matrix, resulting in the development of a versatile nanocomposite material with high antimicrobial and photocatalytic activities under visible light illumination. The nanocomposites were characterized by UV-Vis, FTIR, XRD, SEM, TEM, EDX, XPS, BET, and TPD techniques, confirming the mesoporous nature with Ag, AgCl, and ZnO crystals being uniformly distributed in the polymer matrix. The Ag/ZnO/CMC nanocomposite demonstrated exceptional antibacterial effects on Gram-positive and Gram-negative bacterial strains with an inhibition zone between 30.0 ± 0.8 and 36.0 ± 1.2 mm, which was higher than that achieved by the azithromycin antibiotic on various tested strains. The Ag/ZnO/CMC NC also showed broad-spectrum antibacterial activity, with MIC values of 3.125, 6.25, 6.25, and 12.5 µg mL[-1] against B. subtilis, K. pneumoniae, S. aureus, and S. typhimurium, respectively. In addition, the nanocomposite attained 99.33 ± 1.00% photocatalytic degradation of the Crystal violet dye in 180 minutes under visible light illumination. From the kinetic study, an excellent match was found between the experimental data and the Langmuir-Hinshelwood kinetic model (R [2] = 0.972). In addition, based on the analysis of thermodynamics, it was discovered that the reaction is spontaneous and endothermic. The nanocomposite remained stable with a degradation efficiency of over 91% after five rounds of recycling. The above results reveal that the nanocomposite is highly stable and recyclable. This research study is a sustainable platform for future eco-friendly multifunctional nanocomposites that will help in environmental remediation, wastewater purification, and antimicrobial protection.

The integration of enzyme-loaded polymeric matrices with carbon-based nanomaterials and metallic nanoparticles into wearable multisensing patches, coupled with miniaturized portable detection devices, enables real-time, highly sensitive, and simultaneous monitoring of key clinical biomarkers (e.g., glucose, lactate, and H2O2) in clinical and point-of-care applications. Multiplex biosensors were fabricated by modifying screen-printed carbon paste electrodes (SPEs) with different composite nanomaterials based on carbon nanomaterials such as multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), or fullerenol (FL), the redox mediator Prussian Blue, and platinum nanoparticles (PtNPs). Chitosan and sol-gel polymer matrices were used to immobilize the enzymes glucose oxidase (GOx) and lactate oxidase (LOx), thus ensuring not only increased sensitivity and operational stability, but also high specificity for biomarker detection (glucose and lactate). Among the nanomaterials used for the development of multiplex biosensors, the SWCNT-PtNP composite was highlighted by electrochemical studies as having a significantly superior electrocatalytic activity toward the reduction of H2O2. This reaction occurs at a low applied potential of only -0.2 V vs. Ag/AgCl, achieving a specific sensitivity of 224.6 mA·M-1·cm-2, over a concentration range of 0.07 to 28.26 mM, and a detection limit of 3.2 μM. When functionalized with enzymes, SWCNT-PtNP-based biosensors exhibit improved conductivity, allowing the detection of glucose and lactate at a potential of -0.05 V vs. Ag/AgCl. The specific sensitivities obtained are 20.25 mA·M-1·cm-2 for glucose and 94.76 mA·M-1·cm-2 for lactate, and the corresponding detection limits are 23.6 μM and 5.0 μM, respectively. Finally, a wearable patch integrating the multiplex (bio)sensor with a portable potentiostat enabled simultaneous, sensitive, and selective detection of glucose, lactate, and H2O2 in sweat samples.

The brain's complex network relies on electrical and chemical signaling to support its normal functions. Understanding brain circuits requires simultaneously monitoring neurotransmitters and electrophysiological signals. The striatal dopamine circuits are integral to neurological processes such as reward and circadian rhythm regulation, making it highly desirable to monitor both neural activity and dopamine (DA) levels in freely behaving animals. One promising approach involves the implantation of multimodal microelectrode arrays (MEAs). However, chronic electrochemical sensing of DA in freely moving animals faces significant challenges, including biofouling of sensing electrodes and the instability of the Ag/AgCl reference. In this study, we developed two complementary strategies to coat the implanted Ag/AgCl reference and MEA with zwitterionic poly(sulfobetaine methacrylate) (PSB). The PSB coating effectively inhibits protein fouling and inflammatory responses to the MEA, while the PSB hydrogel protects the Ag/AgCl electrodes from delamination in vivo. We achieved stable DA detection and electrophysiological recordings in freely moving mice over four weeks. Weekly electrochemical impedance spectroscopy confirmed the long-term stability of the implanted electrodes. Our method enables multidimensional analysis of behavioral patterns, electrophysiological activity, and DA dynamics. This work advances neurochemical and electrophysiological methodologies by offering reliable tools for longitudinal investigations of brain function in freely behaving animals.

Direct seawater electrolysis enables on-site offshore renewable conversion, yet simultaneously achieving high activity, selectivity, and long-term stability for the oxygen evolution reaction (OER) under acidic conditions remains challenging. Herein, a series of Ru-doped silver antimonate catalysts are synthesized, among which AgSb0.97Ru0.03O3 delivers optimal performance: an overpotential as low as 92 mV, OER selectivity up to 85%, and robust stability exceeding 40 h at 100 mA cm[-2] in acidic seawater. Theoretical calculations confirm that Ru doping creates new active sites with enhanced charge transfer, and the calculated *OOH adsorption energies correlate well with experimentally observed activity gains. The high selectivity stems from preferential OH[-] adsorption on Ru-OH sites and weakened Ag-Cl affinity that suppresses chlorine evolution, while exceptional stability arises from an insoluble Sb-O skeleton and corrosion-resistant Ru species reinforced by a surface Sb-OH protective layer, preventing structural collapse despite minor Ag[+] leaching. The enhanced activity originates from intrinsically active Ru-OH centers, increased sites via surface hydroxylation, and optimized intermediate binding through d-band center modulation. Notably, compared with pure H2SO4 electrolyte, the presence of appropriate Cl[-] in acidic seawater kinetically synergizes both activity and selectivity by selectively etching inactive surface Ag to expose Sb-Ru-O interfacial sites, enriching local OH[-] via electric double layer modulation, stabilizing Ru oxidation states, and alleviating sulfate poisoning. This work offers a novel anode design strategy for water electrolysis in harsh marine environments, demonstrating promising prospects for direct offshore wind-to-hydrogen applications.