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We present a novel acceleration scheme capable of accelerating electrons and ions in an underdense plasma. Transversely Pumped Acceleration (TPA) uses multiple arrays of counter-propagating laser beamlets that focus onto a central acceleration axis. Tuning the injection timing and the spacing between the adjacent beamlets allows for precise control over the position and velocity of the intersection point of the counter-propagating beam arrays. This results in an accelerating structure that propagates orthogonal to the direction of laser propagation. We present the theory that sets the injection timing of the incoming pulses to accelerate electrons and ions with a tunable phase velocity plasma wave. Simulation results are also presented which demonstrate 1.12 GeV proton beams accelerated in 3.6 mm of plasma and electron acceleration gradients on the order of 1 TeV/m in a scheme that circumvents dephasing. This work has potential applications as a compact accelerator for medical physics and high energy physics colliders.
The challenge in achieving simultaneous electrochemical detection of multiple phytohormones stems from the intricacies involved in delineating oxidation mechanisms of multiple phytohormones, along with the precise delineation of peaks in the electrochemical profiles. Electron-rich phytohormones, which readily participate in electron transfer reactions, possess strong electron-donor properties and can drive redox processes in signal transduction. This work reports electrochemical simultaneous detection of multiple electron-rich phytohormones (indole-3-acetic acid, salicylic acid, and naphthaleneacetic acid) on a portable flexible sensor and virtual visualization. The approach integrates electrochemical investigations with theoretical computations to decipher the intricate oxidation mechanisms of these electron-rich phytohormones at the sensor interface. The number of electrons and protons transferred during the redox processes of the three electron-rich phytohormones were individually quantified via electrochemical method. Furthermore, through calculations and analysis of electronic structure properties-frontier orbital distribution, Fukui function, electroactive sites and oxidation reaction energy barriers-the structure-activity relationship governing the molecular oxidation process is clearly elucidated. This work not only establishes an experimental and virtual visualization platform for the rapid multicomponent electron-rich phytohormones electro-analysis, but also provides an in-depth clarification of their interfacial reaction mechanisms and electron transfer pathways. It reveals distinct differences in the electrochemical behaviors of these phytohormones, thereby advancing the field from empirical monitoring toward rationally designed detection systems.
Excitons play a decisive role in governing light absorption, charge separation, and carrier utilization in low-dimensional photocatalysts. In this work, we present a comprehensive first-principles investigation of excitonic effects and their impact on photocatalytic water splitting in a SnS2/h-BN van der Waals (vdW) heterostructure. Density functional theory (DFT), combined with many-body perturbation theory (MBPT) within the GW approximation and the Bethe-Salpeter equation (BSE), is employed to determine the quasiparticle band edge alignment, exciton binding energies (EBEs), optical absorption, carrier effective masses, and solar-to-hydrogen (STH) conversion efficiency. The SnS2/h-BN heterostructure exhibits a staggered type-II band alignment with quasiparticle band edges straddling the redox potentials, ensuring thermodynamic feasibility for overall water splitting. Beyond band alignment, the heterostructure supports multiple optically active bright interlayer excitons with spatially separated electrons and holes at the interface. These interlayer excitons display reduced electron-hole (e-h) wave function overlap and favorable effective masses, particularly a highly dispersive SnS2-derived conduction band that enables efficient electron transport toward hydrogen evolution reaction sites. Despite their sizable binding energies, efficient exciton dissociation is promoted by strong interfacial electric fields and large conduction band offsets, leading to effective charge separation. Consequently, photogenerated carriers are selectively funneled to distinct catalytic surfaces, enabling spatially separated hydrogen and oxygen evolution. The synergistic enhancement of light absorption, carrier lifetime, and charge transport results in a markedly higher STH efficiency (11.04%) compared to that of pristine SnS2. This work underscores the necessity of explicit excitonic treatment and establishes exciton engineering in vdW heterostructures as a key strategy for the design of efficient photocatalysts for solar water splitting.
Various C₁-C₂ compounds are increasingly available through electrochemical reduction of CO2. Although not always suitable as a sole substrate, these compounds can supplement a primary substrate like glucose to enhance microbial growth. Yet, the mechanisms underlying the effects of dual substrate consumption on growth rate and growth yield remain poorly understood. We developed a generalized, species-agnostic thermodynamic framework to partition anabolic and catabolic fluxes for various glucose/secondary substrate combinations, predicting maximum growth rate and growth yield as a function of the substrate ratio. The optimal strategy is to use the secondary substrate as electron donor, conserving the most efficient carbon source, glucose, for assimilation. Because many substrates yield similar energy per electron, biomass yield remains constant until glucose becomes limiting for anabolism. When further lowering the glucose fraction, additional assimilation of the auxiliary carbon source reduces the yield. The growth rate follows similar trends. Dual substrate growth enables generalists to produce more biomass from the total resource pool than a combination of specialists, conferring a competitive edge under substrate-limiting conditions. These theoretical observations align with experimental observations of lower residual substrate concentrations and dominance of generalists in natural and engineered oligotrophic environments.
Exogenous halide ions in aquatic environments can generate highly toxic halogenated disinfection byproducts during the advanced oxidation process, posing new environmental risks. However, the release of halide ions from widely utilized halide-containing catalysts and subsequent formation of these highly toxic byproducts have largely been overlooked. Herein, in this study, metallic Bi deposited onto BiOI to promote peroxydisulfate (PDS) activation for the degradation of bisphenol A (BPA). The results showed that the degradation rate constant of BPA on Bi/BiOI (0.323 min-1) was 8.97 times higher than that on pristine BiOI (0.036 min-1). Mechanism studies revealed that the active sites (Bi/Bi(III)) of Bi/BiOI undergo strong covalent hybridization with the p-orbitals of oxygen in PDS. This interaction disrupted the local structure of Bi/BiOI, thereby liberating iodide ions (∼0.11 mM). Quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated that the released iodide ions were locally oxidized by surface-adsorbed sulfate (Bi-*SO4·-) into reactive iodine species. Consequently, these reactive iodine species attacked BPA to form highly toxic iodinated byproducts and dimers, as identified via high-performance liquid chromatography-high-resolution mass spectrometry (HPLCHRMS). This study provides new insights into the activation mechanism of PDS by Bi/BiOI and highlights potential environmental risks of deploying BiOX-based catalysts to activate oxidants for pollutants degradation.
Surfactants are widely used in virus disinfection; yet the mechanisms by which they deactivate viruses, particularly Nonenveloped viruses (NEVs), are not understood in detail. We examined the physicochemical interactions of ionic surfactants with viral capsids, correlated them to the residual virus infectivity, and introduced a model that enables prediction of antiviral efficacy based on capsid biomolecular characteristics. Using the MS2 bacteriophage as a NEV model, we assessed the surfactants' antiviral efficacy across a broad pH range using plaque assays. Neither pH changes nor ionic surfactants alone significantly impacted NEVs; however, their combination showed strong synergy. Within a 60 s contact time, >105 viral load reduction was achieved using anionic surfactants at pH < 5 or cationic surfactants at pH > 10. Dynamic and electrophoretic light scattering provided data on surfactant-capsid interactions, which we further explored by molecular modeling of the capsid charge distributions across pH ranges using protein sequence data. These results informed a selective-permeation model describing how surfactant efficacy depends on electrostatic interactions─repulsion, attraction, and permeation─with capsid proteins. The model predictions were validated using transmission electron microscopy and were applied to accurately predict the pH inactivation thresholds of ΦX174 phage. The results indicate that both cationic and anionic surfactants could serve as efficient antiviral agents, if the pH of the system favors surfactant penetration through both the inner and outer layers of the capsids. They offer a theoretical framework for the rational design of antiviral formulations for NEVs.
Direct recovery of phosphorus from Sargassum spp. in the form of magnesium-whitlockite (Ca9.5MgO28P7) was proposed for the first time. The effects of the acid digestion and calcination sequence on the naturally adsorbed minerals in Sargassum spp. were investigated through two treatment approaches (I and II). Treatment I (producing Ash-1) consisted of acid digestion followed by calcination, while Treatment II (producing Ash-2) involved initial calcination, subsequent acid digestion, and a final calcination step. It was found that Treatment I is effective in obtaining ashes containing magnesium-whitlockite (Mg-WH) together with diatoms frustules. Whereas Ash-2 showed an almost complete absence of diatom frustules and phosphate-based components. It was revealed that in Treatment I, a significant fraction of phosphorus, particularly organic ones, were less susceptible to acid digestion and therefore remained intact. During subsequent calcination, together with calcium- and magnesium-containing species, they can be thermally decomposed or oxidized, and Mg-WH will be the preferred final product. In contrast, in Treatment II, the initial calcination predominantly transformed organic phosphorus into acid-soluble inorganic forms, resulting in almost no phosphorus remaining after final calcination. Conclusively, this work unravels the importance of acid digestion and calcination sequence in phosphorus recovery and determining the yield and properties of the minerals. This study can shed light on the requirements and limitations of this efficient treatment in promoting the valorization of marine biomass and supporting sustainable strategies for mitigating the environmental impacts of excessive sargassum proliferation in coastal regions.
Fluorinated gel polymer electrolytes (FGPEs) prepared via in situ polymerization are expected to expedite the large-scale application of lithium metal batteries (LMBs) by enabling stable LiF-rich solid electrolyte interphases (SEIs) and good compatibility with high-voltage cathodes. However, the electron-withdrawing nature of fluorine units retards polymerization kinetics of such monomers, resulting in GPEs with compromised mechanical performance and cycling durability. Herein, a design principle for in situ formation of fluorinated copolymers is proposed to regulate the polymerization kinetics of trifluoroethyl methacrylate (TFEMA)-typed monomers. Such strategy yields relatively uniform polymer chains with moderate molecular weights, which are subsequently crosslinked to form a robust fluorinated-nitrogenated copolymer network (FNPE). The tailored polymer matrix integrates the capabilities to form a LiF-containing SEI promoted by fluorinated segments, enhanced mechanical robustness, and a Li3N-rich interphase contributed by the N-isopropylacrylamide (NIPAM) domains. Consequently, the FNPE achieves NCM811(6.8 mg cm-2, 1.2 mAh cm-2)//Li full cells with high capacity retention (> 80%, 225 cycles), and applicable in wide temperature range (-15 to 60°C) and pouch cell configuration (40 µm Li). Through experimental and multiscale modeling investigations, this work elucidates the intrinsic kinetic challenge for in situ formed FGPEs and provides a new design principle of copolymer-type electrolytes for durable LMBs.
Accurate and up-to-date anatomical information is critical for effective treatment planning in breast cancer adaptive radiotherapy. Cone-beam computed tomography facilitates real-time plan optimization but lacks sufficient electron density accuracy for direct clinical application. To address this limitation, we propose a novel unsupervised deep learning framework that integrates the Mamba architecture with an artifact disentanglement network to form the Artifact Disentanglement Network-Mamba model. This study proposes an unsupervised deep learning framework, ADN-Mamba, integrating an Artifact Disentanglement Network (ADN) with the structured state-space model Mamba for high-precision sCT synthesis from breath-hold CBCT (BH-CBCT). The model uses three encoders (CBCT content, CT content, artifact) and two generators to disentangle anatomical features from artifacts in CBCT. Mamba enhances the ability of the model to capture long-range dependencies, improving representation of complex anatomical structures. The Artifact Disentanglement Network-Mamba model achieved a mean absolute error of 54.97 HU within the body. The mean absolute percent errors of synthetic and real CT images in the soft tissue (-150 HU to 150 HU) and bone (200 HU to 1500 HU) regions were 46.26% and 30.98%, respectively. The gamma pass rate of the calculated dose on sCT compared with that on pCT is 97.74% under the 2%/2 mm criterion. The proposed model outperforms six other state-of-the-art methods in terms of image quality, dose accuracy, and radiomic feature consistency. By overcoming challenges such as registration errors and the absence of paired cone-beam computed tomography-computed tomography datasets, the proposed framework demonstrated superior performance in terms of anatomical fidelity and dose calculation accuracy. ADN-Mamba enables precise BH-CBCT-to-CT synthesis via unsupervised artifact disentanglement and Mamba's long-range modeling, demonstrating superior performance in image quality, dose calculation accuracy, and radiomic consistency. This framework provides a reliable tool for online dose calculation and target delineation in breast ART. Future work will focus on extending the model to 3D data and multicenter validation.
The alarming contamination of aquatic ecosystems with toxic heavy metals and persistent organic dyes demands innovative nanotechnological solutions for simultaneous detection and remediation. In this research, 4-fluorobenzohydrazide-stabilized silver nanoparticles (4-FBH@AgNPs) were synthesized to serve as a versatile nanoplatform for the colorimetric detection of Cd(II), photocatalytic degradation of the methylene blue (MB) dye, and antimicrobial applications. The synthesized nanoparticles were characterized using various techniques, including UV-Visible spectroscopy, FTIR, XRD, TEM, XPS, DLS, zeta potential, and SEM to assess their structural and optical properties. The UV-Vis analysis displayed a distinct localized surface plasmon resonance (LSPR) peak at 435 nm, confirming nanoparticle formation. Colorimetric sensing tests revealed notable color changes for Cd(II), showing a linear response in the nanomolar range with a low limit of detection (LOD) of 37 nM, demonstrating high sensitivity and selectivity towards Cd(II) ions. Additionally, the 4-FBH@AgNPs exhibited impressive photocatalytic efficiency, achieving over 95% degradation of methylene blue (MB) in 60 min under visible light, attributed to improved electron-hole separation and enhanced charge transfer due to plasmon effects. The nanoparticles also exhibited considerable antibacterial properties against Escherichia coli and Staphylococcus aureus. Statistical analysis affirmed the reproducibility and reliability of the photocatalytic and antimicrobial results by response surface methodology. Collectively, these findings demonstrate that 4-FBH@AgNPs possess excellent multifunctional capabilities, making them a promising candidate for environmental remediation and biosensing applications.
aphthalene diimide and derivatives (NDIs) are preferential to construct stable optic gas sensitive hydrogen-bonded organic frameworks (HOFs) owing to their photo-responsive electron accepting-donating conjugated building blocks. In this study, we developed series of NDIs-HOFs films with structural, spectral diversity, and optical gas sensing specificities that vary with the shape or length of the NDIs substituent. A series of NDIs-HOFs films were constructed from benzene dicarboxylic acid (bdc), NDIs (NDI, dpNDI, H4BIPA-TC), and phenylporphyrin sulfonate (TPPS), and were rapidly fabricated on the surface of titanium-dioxide (TiO2) film optical waveguides (OWGs) substrate using UV-light irradiation approach. The surface of NDIs-HOFs films showed different morphologies due to the difference in shapes or length of NDIs, i.e., NDI-HOF showed a spherical shape, dpNDI-HOF showed a straw-like hexagonal shape, and BIPA-TC-HOF showed a smooth plane amorphous structure. The structural diversity of NDIs-HOFs inducing differences in spectral characteristics and gas sensing specificity. Owing to the Lewis base nature of amide bound in NDI central aromatic ring, the NDIs-HOFs films OWGs exhibited sensing response to H2S. The H2S detectability of NDIs-HOFs films OWGs were varied from their structure and pore-size, following the order of NDI-HOF > BIPA-TC-HOF > dpNDI-HOF. Among the series NDIs-HOFs films, NDI-HOF films OWG exhibits most sensitive response (response time: 2 s; detection range: 0.01-10 ppm; limit of detection: 0.92 ppm) to H2S without any interference from the other acid/base gases (e.g., NH3, SO2, NO2, or HCl) and ambient humidity.
The development of stable, environmentally benign, and high-performance perovskite solar cells (PSCs) has increasingly focused on innovative inorganic absorber materials. In this study, we conduct a detailed evaluation of the optoelectronic and mechanical properties of Ca3AsBr3, a promising non-toxic halide perovskite, using density functional theory (DFT) alongside SCAPS-1D simulations. The DFT results indicate that Ca3AsBr3 possesses a direct bandgap of 1.66 eV, along with good mechanical stability and strong optical absorption, making it well-suited for photovoltaic applications. To further investigate device performance, four electron transport layers (ETLs)-WS2, SnS2, CdS, and TiO2 were incorporated into HTL-free FTO/ETL/Ca3AsBr3/Au architecture, allowing analysis of energy band alignment, defect tolerance, and overall efficiency. Among these configurations, the WS₂-based device demonstrated superior performance, achieving a power conversion efficiency (PCE) of 20.50%, with an open-circuit voltage (Voc) of 1.165 V, a short-circuit current density (Jsc) of 20.55 mA/cm², and a fill factor (FF) of 85.64%. Further simulation results highlight that an optimal absorber thickness of 1200 nm, along with reduced bulk and interface defect densities (≤ 10¹⁵ cm⁻³ and ≤ 10¹³ cm⁻²), plays a crucial role in minimizing non-radiative recombination losses and improving charge carrier collection. Overall, this work identifies Ca3AsBr3 as a viable eco-friendly absorber material and emphasizes the importance of ETL optimization in achieving efficient, stable, and scalable PSC devices.
Regarding the unclear influence of Fe-N modification sequences on biochar performance, this study systematically investigated the effects of Fe and N introduction sequences on biochar characteristics using lotus stalk as a precursor, urea as the nitrogen source, and FeCl3·6H2O as the iron source. The novelty of this work lies in revealing the synergistic mechanism of Fe-catalyzed carbon gasification coupled with N etching/cross-linking under simultaneous doping conditions, and establishing a clear structure-activity relationship correlating doping sequence with microstructure and adsorption performance. The optimal modified biochar was screened for AMOX adsorption from aqueous solution, and the adsorption mechanisms were elucidated through multi-scale characterization and batch adsorption experiments. The results show that simultaneous Fe-N doping combined with pyrolysis at 700°C for 4 hours (FeN-BC-4h) induced a synergistic effect of Fe-catalyzed carbon gasification and N etching, constructing a hierarchical pore structure with a specific surface area of 752.06 m2·g-1 and a total pore volume of 0.73 cm3·g-1. The equilibrium adsorption capacity for AMOX reached 130.92 mg·g-1, surpassing samples with single or sequential doping and representing a 2.55-fold enhancement compared to raw biochar. The surface of FeN-BC-4h was highly heterogeneous, with chemisorption dominating the adsorption process. Intraparticle diffusion served as the rate-controlling step, and the adsorption was an endothermic spontaneous reaction that increased system disorder. The adsorption mechanisms included pore filling, π-π electron donor-acceptor interactions, hydrogen bonding, Fe-O/Fe-N coordination complexation, and electrostatic interactions. FeN-BC-4h maintained stable and efficient adsorption within the pH range of 4-9, exhibited magnetic responsiveness, and retained approximately 67.03% of its adsorption capacity after three regeneration cycles via HCl washing. This research provides theoretical insights and technical references for the high-value utilization of lotus stalk-based biochar and the efficient removal of antibiotic pollutants.
The green synthesis of multifunctional nanomaterials from agricultural waste is a major target in sustainable biomedicine. This study reports the eco-friendly, one-pot synthesis of copper-doped titanium dioxide nanoparticles (Cu-TiO2NPs) using an aqueous peel extract of Citrus limon (Linn.) Burm. f. The formation of the nanoparticles was observed using the ultraviolet-visible spectroscopy, with an absorption edge below 400 nm with a redshift in the visible range (400-650 nm). X-ray diffraction (XRD) confirmed a mixed anatase-rutile crystalline phase, with an average crystallite size of 45.6 nm, and scanning electron microscopy (SEM) showed irregularly shaped agglomerated nanoparticles with an average diameter of 48 ± 0.46 nm. Field Emission Scanning Electron Microscopy (FESEM) revealed irregular, highly agglomerated nanoparticles with a primary size range of 49 ± 07 nm, while X-ray Photoelectron Spectroscopy (XPS) confirmed the oxidation states of Ti, O, and Cu, validating successful doping. Energy-Dispersive X-ray (EDX) analysis further confirmed uniform Cu incorporation into the TiO₂ lattice. In vitro testing showed a dose-dependent antibacterial effect against Staphylococcus aureus (ATCC 9144), Staphylococcus epidermidis (ATCC 12228), and Pseudomonas aeruginosa (ATCC 10145), with minimum inhibitory concentration (MIC) values ranging from 15 to 20 µg/mL. The highest zone of inhibition for Cu-TiO₂NPs was 21.00 ± 0.29 mm against S. epidermidis at 30 µg/mL, similar to the effect observed with ceftriaxone (30 µg/mL). The nanoparticles exhibited high antioxidant capacity, with a ferric reducing antioxidant potential of 67.5 ascorbic acid equivalents (AAE) µg/mL and a 54% 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity at 500 µg/mL. Cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, which indicated dose-dependent cytotoxicity in human hepatocellular carcinoma (HepG2) cells, with an IC50 of 150 µg/mL after 24 h. The stabilization of the L-ascorbic acid-Cu-TiO₂NPs complex was investigated using Density Functional Theory (DFT), and molecular docking revealed strong interactions with the target bacteria. This study uniquely integrates sustainable waste valorization, comprehensive in vitro bio evaluation, and computational validation of lemon peel-derived Cu-TiO2NPs for biomedical applications.
Pleurotus florida (P. florida) mushrooms are widely valued for their nutritional, medicinal and bioactive properties. Selenium (Se) biofortification of edible mushrooms offers a sustainable strategy to mitigate global micronutrient deficiencies, however the narrow margin between the nutritional benefits and toxicity of Se necessitates precise physiological optimization. This study presents a comprehensive in vitro evaluation of Se-induced growth modulation, oxidative stress, ultrastructural responses and uptake dynamics in P. florida cultivated under sodium selenite concentrations. Mycelial growth on PDA exhibited a highly reproducible biphasic response across three independent experiments. Low Se concentrations (10-15 mg L⁻¹) significantly enhanced radial growth and biomass accumulation. Elevated concentrations (≥40 mg L⁻¹) caused sharp declines in growth and biomass, accompanied by abnormal colony morphology and reduced mycelial density. Lipid peroxidation analysis revealed a strong dose-dependent increase in oxidative membrane damage, with Se concentration explaining nearly 90% of the observed variation, indicating a shift from antioxidant support at low doses to pro-oxidant toxicity at higher levels. Scanning electron microscopy (SEM) confirmed enhanced hyphal branching and structural organization at optimal Se concentrations, while severe ultrastructural damage including hyphal collapse and filament breakage was evident under high Se stress. Scanning Electron Microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) analysis showed Se-induced alterations in mycelial surface composition and inductively coupled plasma mass spectrometry (ICP-MS) based mass-balance analysis demonstrated high Se removal efficiency (>80%), with excessive biomass-normalized accumulation at high concentrations reflecting stress rather than efficient biofortification. Collectively, this study defines a narrow Se tolerance window in P. florida and identifies 15 mg L⁻¹ as the optimal concentration for safe and effective Se biofortification.
Anaerobic digestion (AD) often suffers operation failure from ammonia inhibition and volatile fatty acids (VFAs) accumulation under high organic loading rates (OLRs). To overcome these limitations, this study employed granular activated carbon coupled with riboflavin (RFGAC) by stimulating direct interspecies electron transfer (DIET). A semi-continuous AD experiment was conducted for 145 days with OLRs ranging from 2.25 to 11.25 kg COD/(m3·d). The results showed that the RFGAC group achieved the highest methane content of 78%, and maintained a COD removal rate above 95%, outperforming the GAC group and the control. At an OLR of 6.75 kg COD/(m3·d), the control collapsed due to severe acidification when the pH dropped lower than 6.5, while the RFGAC group stably operated with effluent COD of 2200-5300 mg/L and seldom VFAs accumulation. Microbial community analysis revealed that RFGAC selectively shifted microbial community composition especially at high OLR, promoting Methanosarcina to form a synergistic consortium. The Pearson correlation analysis of digestion performance and metagenome revealed that Methanosarcina had a stronger correlation with methanogenesis than Methanothrix, which was enriched in the presence of GAC alone. Metabolic pathway analysis confirmed key DIET-related functional genes, hdrA2 and methyl transfer-associated mtrH, were respectively upregulated by 7-fold and 5-fold. This study offers a viable strategy to improve chicken manure AD, and provides deep mechanistic insights on RFGAC modulation of microbial community succession and functional gene expression.
Carbon dot (CD)-based nanozymes have become promising substitutes to natural enzymes in high-performance analytical detection systems, due to their high-water solubility, tunable surface chemistry, and their ability to produce multiple signaling outputs. It has been shown that CDs have a variety of enzyme-mimetic activities, such as peroxidase (POD), oxidase (OXD), and superoxide dismutase (SOD)-like activities, and can be used in bioassays and environmental monitoring. Although such progress has been made, there is still no detailed theoretical framework that explains the origins of their catalytic activity and the mechanisms that underlie sensing selectivity, thus restricting the rational design and optimization of CD-based nanozymes. This is a systematic review of the impact of precursor selection, reaction conditions, and doping strategies on the surface functional groups, defect structures, and metal active centers of CDs. It also explains how these structural features work synergistically to regulate electron transfer processes and active site formation. Furthermore, the review suggests that interfacial noncovalent interactions are the main determinants of the sensing selectivity of CD nanozymes, which is accompanied by molecular recognition processes and energy-level complementation. Recent advances in multimodal signaling strategies to detect complex systems are also mentioned. Lastly, the present issues and future outlooks in the controlled construction and sensing uses of CDs are also pointed out, which can be useful in the rational design and practical use of these new nanozymes.
The development of stable and efficient luminescent organic radicals for sensing applications remains a significant challenge. Herein, we report the design and synthesis of two novel fluorescent probes, TTM-BPA and TTM-Phen, based on a tris(2,4,6-trichlorophenyl)methyl (TTM) radical core functionalized with N,N-bis(pyridin-2-ylmethyl)aniline (BPA) and 1,10-phenanthroline (Phen) moieties, respectively. Both radical probes exhibit intense, deep-red emission that is remarkably insensitive to solvent polarity, a desirable feature for robust sensing applications. The introduction of extended π-conjugated systems dramatically enhanced their photostability by over 300-fold compared to the parent TTM radical. Leveraging the coordination capabilities of the pyridine-based ligands, these probes demonstrate excellent performance as selective chemosensors. TTM-BPA acts as a specific "turn-off" fluorescent probe for ferric ions (Fe3+) and protons (H+), with detection limits of 4.4 μM and 0.65 μM, respectively. TTM-Phen selectively detects both Fe3+ and ferrous ions (Fe2+) with high sensitivity, achieving detection limits of 1.3 μM and 0.92 μM. The sensing mechanism is attributed to fluorescence quenching via an electron transfer process upon coordination with the target analytes. Practical applications have shown that TTM-BPA and TTM-Phen can be used for fluorescence imaging of Fe3+ and Fe2+, as well as for the detection of iron ions in tap water. This work not only presents a new class of highly stable, deep-red emitting radical probes but also provides a versatile platform for the development of advanced sensors for biologically and environmentally important species.
Non-invasive, real-time monitoring of lactate in sweat is critical for personalized health tracking and sports performance optimization. However, conventional enzyme-based lactate sensors suffer from limited stability and high cost, while many reported nanozyme systems exhibit optimal activity only under alkaline conditions, limiting their applicability in physiological environments. In this report, we develop a wearable integrated nanozyme-based electrochemical sensor for sweat lactate monitoring. The sensor comprises cobalt oxide (Co3O4) and cobalt phosphate (Co3(PO4)2) nanoflakes on a screen-printed carbon electrode (SPCE), combined with a microfluidic unit for sweat collection and transport. Co3O4 nanoflakes were electrodeposited and electrochemically activated to form a Co3O4/Co3(PO4)2/SPCE platform for lactate detection. The structural morphologies, surface composition and chemical states, and crystalline information of the modified electrodes were analyzed using various analytical techniques, such as scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The Co3O4/Co3(PO4)2/SPCE exhibited robust electrocatalytic activity for lactate detection at neutral pH, yielding a dynamic range of 1 - 80 mM with a sensitivity of 8.3 μA mM-1 cm-2 and a limit of detection of 0.3 mM. The developed sensor offers good selectivity against common electroactive sweat components (ascorbic acid, uric acid, and glucose). The microfluidic integrated sensor was tested dynamically with different concentrations of lactate, yielding a sensitivity of 5.2 μA mM-1 cm-2. The device was validated by on-body sweat lactate monitoring during cycling, showing excellent accuracy (>91%) versus a colorimetric reference test. The integrated sensor enables real-time sweat lactate analysis for sports monitoring and personalized health tracking.
In this work, PANI/CNT/CC composite is developed as a positive electrode for flexible zinc-ion battery (ZIB) with the high specific capacity. Assembled flexible batteries are subjected to electrochemical testing. A double grid structure constructed by CNT modification of polyaniline nanofiber network on carbon cloth and CNF modification of PAM gel further improved its flexibility and bending ability. The optimized battery exhibits a high specific capacity of 210 mA hg⁻¹ at a current density of 0.5 A g⁻¹, i.e., a marked improvement in rate performance and bending stability. Following 800 charge and discharge cycles at a current density of 2 A g⁻¹, the battery demonstrates an impressive capacity retention rate of approximately 90.6% along with a notable average coulombic efficiency of 98.7%, underscoring its remarkable strength and stability. The PANI/CNT/CC|CNF/PAM|Zn battery can power the device when it is bent or even folded. Such enhanced electrochemical performance of optimized ZIB is originated from synergistic coupling between the 3D cathode and CNF/PAM dual-network hydrogel electrolyte, which simultaneously facilitates electron transport, Zn2+ ion diffusion, and interfacial stability.