Redox Activity Research Articles

A Metastable Oxygen Redox Cathode for Lithium-Ion Batteries.

Simultaneously harnessing cation and anion redox activities in the cathode is crucial for the development of high energy-density lithium-ion batteries. However, achieving long-term stability for both mechanisms remains a significant challenge due to pronounced anisotropic volume changes at low lithium content, unfavorable cation migration, and oxygen loss. Here, we demonstrate exceptionally stable cation and anion redox behavior in a metastable, cobalt-free layered oxide, Li0.693[Li0.153Ni0.190Mn0.657]O2 (LLNMO). After 50 cycles at 50 mA/g (~0.2 C), the cathode retains 97.4% of its initial capacity (222.4 mAh/g) with negligible voltage decay. This remarkable stability is attributed to its metastable rhombohedral symmetry (R-3m) with unique local structures. The face-sharing connectivity between lithium layers and alternating transition metal (TM) layers effectively suppresses TM migration-induced voltage decay during anion redox. Additionally, the structure balances interlayer cation/cation and anion/anion repulsions, resulting in minimal expansion and contraction during de-/lithiation (< 2.3% along the c-axis) and excellent structural reversibility. These findings highlight that layered oxides with a metastable framework are promising cathode candidates for next-generation ultra-high-energy lithium-ion batteries.

Enhanced Anticancer Selectivity of Cyclometalated Imidazole/Pyrazole-Imine IridiumIII Complexes Through the Switch from Cationic to Zwitterionic Forms.

Cyclometalated iridiumIII complexes have shown promising anticancer properties, with variations in charge and ligand substitution significantly influencing their biological activity. However, zwitterionic iridiumIII complexes remain scarcely explored. Herein, we report a series of zwitterionic cyclometalated imidazole/pyrazole-imine iridiumIII complexes and compare their biological activity to analogous cationic complexes with sulfonate counteranions. X-ray crystallography confirmed the structural differences between the cationic and zwitterionic forms. These complexes exhibited cytotoxicity against A549, HeLa, and HepG2 cancer cells, with IC50 values ranging from 14.35 to 69.12 μM. While cationic complexes showed higher cytotoxicity, zwitterionic complexes demonstrated enhanced selectivity for A549 cancer cells over BEAS-2B normal cells (selectivity index: 3.72-5.90 for zwitterionic forms vs 1.16-1.44 for cationic forms). This selectivity is attributed to distinct cellular uptake mechanisms: zwitterionic complexes use an energy-dependent pathway in cancer cells and an energy-independent pathway in normal cells, leading to differences in cellular accumulation and redox activity. Mechanistic studies revealed that both complex types induce ROS generation and mitochondrial membrane depolarization (MMP), with apoptosis as the primary cell death pathway.

A semisynthetic, multicofactor artificial metalloenzyme retains independent site activity.

Native metalloenzymes are unparalleled in their ability to perform efficient small molecule activation reactions, converting simple substrates into complex products. Most of these natural systems possess multiple metallocofactors to facilitate electron transfer or cascade catalysis. While the field of artificial metalloenzymes is growing at a rapid rate, examples of artificial enzymes that leverage two distinct cofactors remain scarce. In this work, we describe a new class of artificial enzymes containing two different metallocofactors, incorporated through bioorthogonal strategies. Nickel-substituted rubredoxin (NiRd), which is a structural and functional mimic of [NiFe] hydrogenases, is used as a scaffold. Incorporation of a synthetic bimetallic inorganic complex based on a macrocyclic biquinazoline ligand (MMBQ) was accomplished using a novel chelating thioether linker. Neither the structure of the NiRd active site nor the MMBQ were altered upon attachment, and each site retained independent redox activity. Electrocatalysis was observed from each site, with the switchability of the system demonstrated through the use of catalytically inert metal centers. This MMBQ-NiRd platform offers a new avenue to create multicofactor artificial metalloenzymes in a robust system that can be easily tuned both through modifications to the protein scaffold and the synthetic moiety, with applications for redox catalysis and tandem reactivity.

Interconnected Lamellar 3D Semiconductive PCP for Rechargeable Aqueous Zinc Battery Cathodes.

2D electronically conductive porous coordination polymers/metal-organic frameworks (2D EC-MOFs) of M-HHTPs (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene; M = Co, Ni, Cu, etc.) have received extensive attention due to their ease of preparation, semiconductive properties, and tunability based on the choice of metal species. However, slight shifts between layers attenuate their specific surface area and stability. In this study, the metal-ion bridge strategy is newly adopted and a vanadyl counterpart of M-HHTP is synthesized with a chemical formula of (VO)3(HHTP)2, hereafter referred to as VO-HHTP. The semiconductor VO-HHTP has a vertical interconnection by octahedral VO6 chains and exhibits a relatively high specific surface area (ca. 590 m2g-1) compared to other 2D EC-MOFs. Motivated by its redox activity and porous nature, VO-HHTP is applied as the cathode material in rechargeable aqueous zinc batteries (RAZBs). VO-HHTP demonstrates a high capacity of 240 mAh g-1 and excellent rate capability, even with a reduced amount of conductive agent, surpassing the performance of the previous EC-MOFs. Furthermore, its stable structure ensures long-term cycling stability, addressing a common issue in previous EC-MOFs. The work contributes to the development of new concepts in both the design of π-conjugated EC-MOFs and the study of cathode materials for RAZBs.

3D Printed Spectroelectrochemical Platform for Redox-Based Bioelectronics.

Redox provides unique opportunities for interconverting molecular/biological information into electronic signals. Here, the fabrication of a 3D-printed multiwell device that can be interfaced into existing laboratory instruments (e.g., well-plate readers and microscopes) to enable advanced redox-based spectral and electrochemical capabilities is reported. In the first application, mediated probing is used as a soft sensing method for biomanufacturing: it is shown that electrochemical signal metrics can discern intact mAbs from partially reduced mAb variants (fragmentation), and that these near-real-time electrical measurements correlate to off-line chemical analysis. In the second application, operando spectroelectrochemical measurements are used to characterize a redox-active catechol-based hydrogel film: it is shown that electron transfer into/from the film correlates to the molecular switching of the film's redox state with the film's absorbance increasing upon oxidation and the film's fluorescence increasing upon reduction. In the final example, a synthetic biofilm containing redox-responsive E. coli is electro-assembled: it is shown that gene expression can be induced under reducing conditions (via reductive H2O2 generation) or oxidative conditions (via oxidation of a phenolic redox-signaling molecule). Overall, this work demonstrates that 3D printing allows the fabrication of bespoke electrochemical devices that can accelerate the understanding of redox-based phenomena in biology and enable the detection/characterization redox activities in technology.

Strategic Nitrogen Site Alignment in Covalent Organic Frameworks for Enhanced Performance in Aqueous Zinc‐Iodide Batteries

AbstractAqueous zinc‐iodine batteries (AZIBs) are gaining attention as next‐generation energy storage systems due to their high theoretical capacity, enhanced safety, and cost‐effectiveness. However, their practical application is hindered by challenges such as slow reaction kinetics and the persistent polyiodide shuttle effect. To address these limitations, we developed a novel class of covalent organic frameworks (COFs) featuring electron‐rich nitrogen sites with varied density and distribution (N1‐N4) along the pore walls. These nitrogen sites enhance iodine species confinement and mass transport. Our experimental and theoretical studies reveal that the continuous and optimized distribution of nitrogen sites within the COF structure significantly reduces internal resistance and boosts redox activity. Moreover, the N4‐COF demonstrates superior performance compared to other porous materials, due to its high density and strategic alignment of active sites. The I2@N4‐COF cathode achieves a remarkable specific capacity of 348 mAh g−1 at 1 C, almost 1.8 times greater than that of the I2@N1‐COF, while also maintaining excellent cycling stability. This integration of a porous framework with aligned nitrogen sites in the N4‐COF structure not only enhances iodine redox behavior but also offers a promising design strategy for developing high‐performance AZIB electrodes.

SiO2-Mediated Hydrothermal Synthesis of Spiroffite-Type Co2Te3O8.

The hydrothermal synthesis of novel materials typically relies on both knowledge of the redox activities of all cations present in the reaction solution and a small toolset of so-called mineralizers to tune the solution's overall chemical potential. Upon the use of a less conventional mineralizer species, SiO2, we show the stabilization of spiroffite-type Co2Te3O8 under less forceful hydrothermal conditions than those in previous reports. When synthesized in the presence of both SiO2 and each respective alkali carbonate as a secondary mineralizer, silicon substitution in place of tellurium in the host structure becomes apparent, and the corresponding disorder introduced gives rise to enhanced low-temperature ferromagnetism. Our results highlight the complexities of underutilized and combined mineralizer species in the stabilization and tuning of complex magnetic ground states via hydrothermal synthesis techniques.

Rational Regulation of High-Entropy Perovskite Oxides through Hole Doping for Efficient Oxygen Electrocatalysis.

Due to the high configuration entropy, unique atomic arrangement, and electronic structures, high-entropy materials are being actively pursued as bifunctional catalysts for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable zinc-air batteries (ZABs). However, a relevant strategy to enhance the catalytic activity of high-entropy materials is still lacking. Herein, a hole doping strategy has been employed to enable the high-entropy perovskite La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 to effectively catalyze the ORR and OER. Hole doping experiments rely on the substitution of Sr2+ for La3+. The optimized La0.7Sr0.3(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 displays remarkable activity for the ORR and the OER, with a low potential difference of 0.880 V between the half-wave potential of the ORR and the OER potential at 10 mA cm-2, exceeding the majority of perovskite bifunctional catalysts. Further analysis of the electronic structures reveals that hole doping could regulate the eg-orbital filling of the transition-metal cations in high-entropy perovskites to an ideal position and thereby generate many highly active sites to promote the redox activity of oxygen. The assembled rechargeable ZAB with the targeted high-entropy perovskite as the cathode affords a specific capacity of 774.5 mAh gZn-1 under 10 mA cm-2 and durability for a period of 300 cycles, comparable to that of the 20%Pt/C + RuO2 ZAB. This work offers an important approach for the advancement of efficient high-entropy perovskites for ZABs.

Salvianolic acid B drives gluconeogenesis and peroxisomal redox remodeling in cardiac ischemia/reperfusion injury: A metabolism regulation by metabolite signal crosstalk.

Cardiac metabolism relies on glycogen conversion by glycolysis. Glycolysis intersects fatty acid oxidation and often directs a signal crosstalk between redox metabolites. Myocardium with ischemia/reperfusion significantly diverts from normal metabolism. Prospectively, peroxisome lies central to metabolism and redox changes, but mechanisms underlying in ischemia/reperfusion remain undefined. This work aims at investigating the potential effects and mechanisms of Salvianolic acid B (Sal B) in cardioprotection through metabolic remodeling. Following experiments, we found that Sal B is absorbed in blood and rat hearts and its cardiac absorption prevents ischemia/reperfusion injury. Sal B cardioprotection relates to gluconeogenesis activation and peroxisomal redox remodeling. Gluconeogenesis compensates glycogen synthesis through upregulating pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase. Gluconeogenic PC activity drives peroxisomal Pex2/Pex3 expressions and promotes the proliferation of peroxisome. Peroxisome quality control is enhanced with Pex5/Pex14/Pex13/Pex2 transcriptions. Nono, a non-POU domain-containing octamer-binding protein, promotes upregulation of gluconeogenic PC and peroxisomal gene transcripts through transcriptionally splicing their pre-RNAs at octamer duplex. Nono also controls the expression of SARM1/PARP1/sirtuin1 for catalyzing nicotinamide adenine dinucleotide (NAD+) consumption, leading to endurable redox capacities of peroxisome. Peroxisomal redox remodeling alters reactive oxygen species (ROS) and NAD+ contents, following which NAD+ affects cardiac accumulation of physiologically harmful glucocorticoid. In the tests of Sal B combinational treatments, results indicate ROS upregulation whereas NAD+ downregulation with glucocorticoid, ROS scavenging and glucocorticoid elimination with NAD+ precursor, and NAD+ promotion with ROS scavenger, respectively. This metabolite signal crosstalk alternatively antagonizes/agonizes Sal B cardioprotective functions on electrocardiographic output and infarction. Taken together, we reported a cardiac metabolism regulation with Sal B, capable of preventing myocardium from ischemia/reperfusion injury. The metabolite signal crosstalk was achieved by coupling reaction cascades between gluconeogenesis and peroxisomal redox remodeling.

Selective gold extraction from e-waste leachate via sulfur-redox mechanisms using sulfhydryl-functionalized MOFs.

Urban mining of precious metals from electronic waste (e-waste) offers a dual advantage by addressing solid waste management challenges and supplying high-value metals for diverse applications. However, traditional extraction methods generally suffer from poor selectivity and limited capacity in complex acidic leachate. Herein, we present a sulfhydryl-functionalized zirconium-based metal-organic framework (Zr-MSA-AA) as a recyclable and highly selective adsorbent for efficient gold recovery. Specifically, the Zr-MSA-AA exhibits high recovery capacity (1021 mg g-1), remarkable pH-universal, and superb selectivity (Kd of 2.2 × 107 mL g-1) for gold ions across wide pH range and competitive conditions. Comprehensive mechanistic investigations highlight the pivotal role of sulfhydryl groups in selectively capturing gold ions. The redox-transformation of sulfhydryl and sulfonic acid groups mediated the reduction of Au(III) to Au(0) through the nucleation of chlorine-stabilized gold clusters. This unique mechanism, driven by the redox activity of designed sulfhydryl sites, not only mitigates interference from competing cations but also facilitates rapid adsorption kinetics (kf of 1.17 × 10-7 m s-1) for gold ions, surpassing the performance of previous adsorbents. Consequently, Zr-MSA-AA demonstrates exceptional practical applicability, achieving high-purity gold recovery (23.8 Karat) from real e-waste leachate through straightforward physical separation methods. This study introduces an alternative practical strategy for utilizing sulfur's redox activity in adsorbent design, advancing the sustainable recycling of non-renewable metal resources while contributing to environmental conservation.

New insights into chitosan-Ag nanocomposites synthesis: Physicochemical aspects of formation, structure-bioactivity relationship and mechanism of antioxidant activity.

Herein, a novel approach to the controlled formation of chitosan-Ag nanocomposites (NCs) with different structures and tunable chemical/biological properties was proposed. The chitosan-Ag NCs were obtained using hydrothermal synthesis and varying the concentrations of components. The hypothesis of chitosan-Ag NC synthesis using polysaccharide coils as a "microreactor" system was confirmed. A comparative analysis of the physicochemical characteristics of the NCs with single core-shell and multi-core-shell structures was carried out, and the "structure-property" relationship was revealed. The obtained NCs exhibited excellent antiradical properties, comparable to the activity of phenolic acids: the IC50 values were 0.051, 0.022, and 0.019 mg/mL for CS7, CS5, and caffeic acid, respectively. A mechanism for the antiradical activity of chitosan-Ag NCs was discussed. The redox activity of the NCs was found to be 11.4 and 2.3 mg ABTS per 1 mg of Ag in CS5 and CS7, respectively. The proposed environmentally friendly one-pot, one-step synthesis of silver nanoparticles inside chitosan "microreactors" represents an innovative approach to designing hybrid materials with nanoscale control of desired structure and properties. These findings pave the way for further optimization of biopolymer‑silver nanostructures for various biomedical and industrial applications, including the design of a new type of hybrid catalysts such as nanozymes.

NTRC mediates the coupling of chloroplast redox rhythm with nuclear circadian clock in plant cells.

The intricate interplay between cellular circadian rhythms, primarily manifested in the chloroplast redox oscillations-characterized by diel hyperoxidation/reduction cycles of 2-Cys Peroxiredoxins-and the nuclear transcription/translation feedback loop (TTFL) machinery within plant cells, demonstrates a remarkable temporal coherence. However, the molecular mechanisms underlying the integration of these circadian rhythms remain elusive. Here, we elucidate that the chloroplast redox protein, NADPH-dependent thioredoxin reductase type-C (NTRC), modulates the integration of the chloroplast redox rhythms and nuclear circadian clocks by regulating intracellular levels of reactive oxygen species and sucrose. In NTRC-deficient ntrc mutants, the perturbed temporal dynamics of cytosolic metabolite pools substantially attenuated the amplitude of CIRCADIAN CLOCK ASSOCIATED-1 (CCA1) mRNA oscillation, while maintaining its inherent periodicity. In contrast, these fluctuations extended the period and ameliorated the amplitude of GIGANTEA (GI). In alignment with its regulatory role, the chloroplast redox rhythm and TTFL-driven nuclear oscillators are severely disrupted in ntrc plants. The impairments are rescued by NTRC expression, but not by the catalytically inactive NTRC(C/S) mutant, indicating that NTRC's redox activity is essential for synchronizing intracellular circadian rhythms. In return, the canonical nuclear clock component, TIMING OF CAB EXPRESSION-1 (TOC1), regulates the diel chloroplast redox rhythm by controlling NTRC expression, as evidenced by the redox cycle of chloroplast 2-Cys Peroxiredoxins. This reciprocal regulation suggests a tight coupling between chloroplast redox rhythms and nuclear oscillators. Consequently, our research has successfully identified NTRC as a key circadian modulator, elucidating the intricate connection between the metabolite-dependent chloroplast redox rhythm and the temporal dynamics of nuclear canonical clocks.

Homogenized Upcycling for Spent LiNi0.5Co0.2Mn0.3O2: Modulating O Vacancies toward Enhanced Structural Stability

AbstractFascinated by the high value and low pollution, the direct recycling of spent LiNi0.5Co0.2Mn0.3O2 (S‐NCM) has triggered plenty of exploring activities. Considering different industry sources, they always display various particle sizes and surface traits. Therefore, the simple recovery of chemical defects hardly meets the market demand. Herein, the homogenized strategy, containing physical crushing and chemical recovering, is introduced to regenerate morphology and components of S‐NCM, where the successfully regenerated samples displayed uniform particle size and stable chemical lattice. Assisted by physical crushing, the precursors show a large contacting area with oxygen during morphology reconstruction, accompanied by the effective repairing of the internal lattice. More significantly, the unique manner induces the repairing of oxygen vacancies (OVs) and the lowering of Li/Ni disorder, bringing about enhanced structural stability. Moreover, the lowering of oxygen redox activity and the improvement of oxygen binding energy are further revealed by theoretical calculations. The as‐optimized regenerated samples display a considerable capacity of 139.6 mAh g−1 with a remarkable capacity retention of 94% at 1.0 C. Even at 5.0 C, its capacity retention could be kept at ≈80.8% after 150 loops. Given this, this work is expected to provide effective guidance for different NCM regenerations, meanwhile offering an in‐depth understanding of morphology/lattice reconstruction.

Strategic Nitrogen Site Alignment in Covalent Organic Frameworks for Enhanced Performance in Aqueous Zinc-Iodide Batteries.

Aqueous zinc-iodine batteries (AZIBs) are gaining attention as next-generation energy storage systems due to their high theoretical capacity, enhanced safety, and cost-effectiveness. However, their practical application is hindered by challenges such as slow reaction kinetics and the persistent polyiodide shuttle effect. To address these limitations, we developed a novel class of covalent organic frameworks (COFs) featuring electron-rich nitrogen sites with varied density and distribution (N1-N4) along the pore walls. These nitrogen sites enhance iodine species confinement and mass transport. Our experimental and theoretical studies reveal that the continuous and optimized distribution of nitrogen sites within the COF structure significantly reduces internal resistance and boosts redox activity. Moreover, the N4-COF demonstrates superior performance compared to other porous materials, due to its high density and strategic alignment of active sites. The I2@N4-COF cathode achieves a remarkable specific capacity of 348 mAh g⁻¹ at 1 C, almost 1.8 times greater than that of the I2@N1-COF, while also maintaining excellent cycling stability. This integration of a porous framework with aligned nitrogen sites in the N4-COF structure not only enhances iodine redox behavior but also offers a promising design strategy for developing high-performance AZIB electrodes.

Tuning Fork Scanning Electrochemical Cell Microscopy for Resolving Morphological and Redox Properties of Single Ag Nanowires.

We report a Tuning Fork Scanning Electrochemical Cell Microscopy (TF-SECCM) technique for providing morphological and electrochemical information on single redox-active entities. This new operation configuration of SECCM utilizes an electrolyte-filled nanopipette tip mounted onto a tuning fork force sensor to obtain a precise tip-sample distance control and surface morphological mapping capabilities. Redox activities of regions of interest (ROIs) can be investigated by scanning electrode potential by moving the nanopipette to any target regions while maintaining the constant force engagement of the tip with the sample. Using silver nanowires (Ag NWs) as a model system due to their extensive utilization in energy and sensing devices, TF-SECCM provides not only the topography of single Ag NWs but also their distinctive redox activities, catalytic hydrogen evolution reaction (HER) activities, and electrolyte anion adsorption/desorption features in contrast to NW bundles and a supporting substrate.

Employing Triphenylene-Based, Layered, Conductive Metal-Organic Framework Materials as Electrochemical Sensors for Nitric Oxide in Aqueous Media.

This paper describes the first use of conductive metal-organic frameworks as the active material in the electrochemical detection of nitric oxide in aqueous solution. Four hexahydroxytriphenylene (HHTP)-based MOFs linked with first-row transition metal nodes (M = Co, Ni, Cu, Zn) were compared as thin-film working electrodes for promoting oxidation of NO using voltammetric and amperometric techniques. Cu- and Ni-linked MOF analogs provided signal enhancement of 5- to 7-fold over a control glassy carbon electrode (SANO = 6.7 ± 1.2 and 5.7 ± 1.1 for Ni3(HHTP)2 and Cu3(HHTP)2, respectively) for detecting micromolar concentrations of NO. Zinc-based MOF electrodes offered more limited enhancement (SANO = 3.1 ± 0.5), while the cobalt-based MOF analog had intrinsic redox activity at potentials close to NO oxidation, which interfered with sensing. Combining MOFs with a conductive polymer improved electrode stability under repeated electrochemical scanning (14 ± 3% decrease in signal over 10 scans). The stabilized Ni3(HHTP)2@polymer-coated electrodes were able to detect NO at physiologically relevant concentrations (LOD = 9.0 ± 4.8 nM) in amperometric sensing experiments, and exhibited moderate selectivity against ascorbic acid and nitrite (log kj,NO = -1.3 ± 0.3 and -0.83 ± 0.68 for ascorbic acid and nitrite, respectively). This study demonstrates that layered, conductive 2D MOFs have promising applicability for NO detection in aqueous environments.

Side-Gated Iontronic Memtransistor: A Fast and Energy-Efficient Neuromorphic Building Block.

Iontronic memtransistors have emerged as technologically superior to conventional memristors for neuromorphic applications due to their low operating voltage, additional gate control, and enhanced energy efficiency. In this study, a side-gated iontronic organic memtransistor (SG-IOMT) device is explored as a potential energy-efficient hardware building block for fast neuromorphic computing. Its operational flexibility, which encompasses the complex integration of redox activities, ion dynamics, and polaron generation, makes this device intriguing for simultaneous information storage and processing, as it effectively overcomes the von Neumann bottleneck of conventional computing. The SG-IOMT device achieves linear channel conductance performance metrics with switching speeds in the microsecond range and energy efficiency down to a few femtojoules, comparable to those of the brain. This finding demonstrates robustness, supporting the Atkinson-Shiffrin memorization model, and the four most common Hebbian learning rules. Overall, this SG-IOMT device architecture offers significant advantages over conventional architectures, as it yields remarkable image classification performance in convolutional neural network simulations.

Discrete Hybrid Vanadium-oxo Cluster as a Targeted Tool for Selective Protein Oxidative Modifications and Cleavage.

Understanding the impact of oxidative modification on protein structure and functions is essential for developing therapeutic strategies to combat macromolecular damage and cell death. However, selectively inducing oxidative modifications in proteinsremains challenging. Herein we demonstrate that [V6O13{(OCH2)3CCH2OH}2]2-(V6-OH) hybrid metal-oxo cluster can be used for selective protein oxidative cleavage and modifications. We present the first example of a protein-bound hybrid vanadate cluster, whereinteractions with protein surfaces and the redox activity of vanadium enable selective oxidative modifications. Single Crystal X-ray Diffraction (SC-XRD) of the V6-OH and hen egg white lysozyme (HEWL) complex revealed that the binding is dictated both by the inorganic core and the organic ligands attached to it. Selective modifications of HEWL occurs under physiological conditions by producing reactive oxygen species in presence of ascorbate as a reducing agent. The oxidative reaction can be tuned by varying the concentration of V6-OH to result either in selective oxidation of side chains or peptide bond cleavage. LC-MS and crystallography revealed that oxidative modifications were mainly concentrated near the cluster binding sites, providing spatial control of ROS production. This study advances our understanding of vanadium role in biological systems and demonstrates the potential of hybrid metal-oxo clusters in protein modification.

Al and Zn Doping in InON Thin Films and Their Optical, Electrical, and Electrochromic Properties.

Indium oxynitride (InON) is a promising material for various applications due to its notable properties, including high mobility, stability, and visible light transparency. Despite its potential, research on InON's electrochromic (EC) properties, especially after doping, remains limited. This study employed DC magnetron sputtering to prepare InON films under various doping conditions. A comprehensive investigation was conducted to examine the impacts of aluminum (Al) and zinc (Zn) doping on the composition, structure, morphology, optical, electrical, and EC characteristics of the InON films. The results indicated that Al doping increased surface amino groups, roughness, and optical band gap while enhancing redox activity. Zn doping introduced ZnO crystalline peaks, smoothed the surface, and reduced the optical bandgap and electrochemical performance. Both doping types negatively affected optical modulation but enabled the tuning of EC response peaks and wavelength ranges. This research underscores the significant role of doping in optimizing the EC performance of InON films, highlighting their potential for advanced applications.

V4O7 microcubes as an alternative to peroxidase/TMB for colorimetric detection of H2O2: Development of glucose sensing method.

The study focuses on the synthesis of V4O7 microcubes for the non-enzymatic colorimetric determination of H2O2.Vanadium oxide nanostructures are known for their redox activity and layered structures, making V4O7 a valuable material for sensing applications. The characterization of the prepared sample was done using XPS, XRD, Raman spectroscopy, and SEM techniques. The V4O7 microcube showed a rapid response to H2O2 through direct color change without the need for peroxidase enzymes or TMB. Upon exposure to H2O2, the mixed valence V4O7 oxidized to produce V2O5, enabling sensitive detection of H2O2. The V4O7 sensing system exhibited a wide linear response range from 0.025 to 300µM with a low detection limit of 7.6nM for H2O2 detection. When combined with glucose oxidase, the system could detect glucose levels as low as 18nM within a linear range of 0.05µM to 300µM. The proposed sensor demonstrated high selectivity and robust potential for sensing H2O2 in biological samples. The system offers advantages such as fast response, simple operation, naked-eye observation, and cost-effectiveness. The novel sensing system holds promise for visual detection in H2O2 diagnostic clinics, highlighting its potential for practical applications in healthcare settings.