ACS Applied Nano Materials最新文献

Bacterial cellulose (BC) is a clinically established nanofibrillar wound dressing material that promotes healing by maintaining a moist and protected wound microenvironment. BC dressings can remain on wounds for extended periods, improving patient outcomes and reducing healthcare costs. However, BC lacks intrinsic antimicrobial properties, and infections in contaminated wounds remain a clinical concern, particularly in vulnerable patient populations. In this study, we present a benign and scalable self-assembly strategy to functionalize clinically used BC dressings with presynthesized colloidal silver nanoparticles (AgNPs) and antimicrobial peptides (C5), resulting in dual-action antimicrobial activity while preserving beneficial BC material properties. Colloidal AgNPs were efficiently adsorbed into the BC matrix by tailoring the interaction potential between the BC nanofibrils and the nanoparticles. Subsequent functionalization with C5 provided complementary antimicrobial mechanisms. The resulting dressings exhibited potent antimicrobial activity against Staphylococcus aureus, while maintaining high cytocompatibility with human primary keratinocytes and fibroblasts. By enabling tunable silver content, improved antimicrobial performance, and low cytotoxicity, the platform offers a promising route toward infection control in hard-to-heal wounds using clinically approved advanced BC dressings.

Developing efficient and stable photocatalysts for CO₂ reduction under visible light remains a significant challenge in solar energy conversion. In this study, we report a rational design of an amide-bonded ZnIn₂S₄/CoTCPP nanocomposite by covalently coupling amino-functionalized ZnIn₂S₄ (ZIS) with a cobalt porphyrin (CoTCPP) molecular catalyst. The formation of an amide linkage at the semiconductor–molecular interface promotes effective charge transfer and suppresses charge recombination, thus significantly enhancing photocatalytic CO₂ reduction. The optimized ZIS/CoTCPP-4 composite achieved a remarkable CO production rate of 2956.7 μmol·g^–1·h^–1 under solar-light irradiation, which was 32 times higher than that of pristine ZIS, representing one of the highest CO₂-to-CO photoreduction performances reported for ZnIn₂S₄-based photocatalysts. Furthermore, the establishment of a type-II heterojunction between ZIS and CoTCPP helps facilitate spatial charge separation and directional charge transfer, thereby enhancing photocatalytic efficiency. This work highlights the critical role of interfacial engineering via an amide linkage in enhancing light absorption and charge migration, providing an inspiration for constructing high-efficiency chemical bonded photocatalysts for solar-driven CO₂ conversion.

Accurate voltammetric determination of paracetamol (acetaminophen; ACT), nitrite (NO₂^–), and sildenafil (SILD) analytes in a single step is highly required yet challenging in biofluids and pharmaceutical matrices. Herein, samarium oxide (Sm₂O₃) with rod-like morphology was synthesized via a direct hydrothermal route, followed by thermal treatment at 400 °C. The Sm(OH)₃ nanorods (NRs) were initially formed and subsequently transformed into cubic crystals of Sm₂O₃ NRs with an average diameter of 50 nm and a length of 0.6 μm. The resulting Sm₂O₃ NRs exhibit well-defined surface cavities, high surface exposure, and preferential crystallographic growth, which are desired for enhancing electron-transfer processes. The Sm₂O₃ NRs were drop-cast onto screen-printed carbon electrodes (SPEs) and employed as a nonenzymatic platform for simultaneous electrochemical analysis of ACT, SILD, and NO₂^–. Well-resolved oxidation peaks of ACT, NO₂^–, and SILD were observed on the Sm₂O₃ NRs-SPEs at 0.57, 0.81, and 1.30 V (vs Ag/AgCl), respectively, in Britton–Robinson (B.R.) buffer of pH 2.0. The potential peak separation enabled sensitive individual and simultaneous analysis of the target analytes in wide concentration ranges of 2.65–2511.72 μmol/L ACT, 14.97–8849.79 μmol/L NO₂^–, and 0.49–1316.95 μmol/L SILD with low limit of detections (LODs) of 1.24 μmol/L, 1.477 μmol/L, and 97 nmol/L, respectively. Exceptional selectivity, stability, and recovery in pharmaceutical formulations and biological samples underscore the potential of Sm₂O₃ NRs-SPE as a promising electrochemical sensor for multianalytes.

We present a facile methodology for ammonia (NH₃) synthesis using a multiphase iron nanocatalyst (r-IOD (Fe@Fe₃O₄@Fe₂O₃)) under ambient conditions. Structural and physicochemical analyses of r-IOD were conducted using pXRD, Mössbauer spectroscopy, HRTEM, and XPS analyses, where r-IOD features a three-phase composite architecture, enabling room-temperature reduction of nitrate (NO₃^–) to NH₃. The NH₃ formation was confirmed by ¹⁵N isotope labeling and ¹H NMR analysis and quantified by UV-Vis spectroscopic analysis. Postreaction UV-DRS and XRD of r-IOD were also analyzed, indicating Fe-redox participation in the process of NO₃^– reduction.

In response to the urgent demand for sustainable and clean energy solutions, photoelectrochemical (PEC) water splitting is a leading approach for effectively producing green hydrogen (H₂). BiVO₄ photoanodes are among the best materials available for visible-light-driven water oxidation. However, their performance is hindered by rapid charge-carrier recombination and inadequate photostability. Therefore, the surface of nanodendritic BiVO₄ is modified with an iron oxyhydroxide (β-FeOOH) cocatalyst, which is obtained via a pH-controlled dip-coating method. A saturation photocurrent density of 2.73 mA cm^–2 at +1.4 V versus RHE under AM 1.5 G illumination is observed, which shows a 1.8-fold enhancement over that of pristine BiVO₄. The applied bias photon-to-current efficiency (ABPE) reflects a striking 3.45-fold increment for the heterojunction. The incident photon-to-current conversion efficiency (IPCE) measurements indicate that the heterojunction is twice as efficient as pristine BiVO₄. The BiVO₄/β-FeOOH heterojunction has significantly facilitated interfacial charge transfer, resulting in an increase in charge transfer efficiency from 35.73% to 58.24%, which reflects a noticeable reduction in electron–hole recombination. The oxidation of water molecules proceeds via a peroxo intermediate, which is confirmed by Fourier transform infrared (FTIR) spectroscopy. The Mott–Schottky analysis shows an enhanced charge carrier density, 3.61 times for the optimized BiVO₄/FeOOH heterostructure. According to the band edge alignment determined by ultraviolet photoelectron spectroscopy (UPS) analysis, a type-II heterojunction is formed between BiVO₄ and β-FeOOH, which efficiently separates the photogenerated excitons and promotes water oxidation, boosting its PEC performance. Hence, this study demonstrates that integrating the β-FeOOH cocatalyst is an effective strategy for overcoming the intrinsic limitations of BiVO₄, paving the way for advancing the development of efficient photoanodes for solar-driven H₂ production.

The extensive veterinary use of ronidazole (RZ), a nitroimidazole-class antiparasitic drug, has raised concerns regarding its environmental persistence, bioaccumulation in food products, and potential health risks. Herein, we report a highly sensitive electrochemical sensor based on a sulfur-doped tungsten oxide/hierarchical porous biocarbon (S-WO₃/HPBC) composite-modified glassy carbon electrode (GCE) for selective RZ detection. S-WO₃ was synthesized via a hydrothermal–ethanol crystallization–calcination route, while three-dimensional HPBC was derived from custard apple seeds through carbonization, KOH activation, and acid neutralization, providing a conductive, high-surface-area scaffold. The composite was assembled under reflux in a nitrogen atmosphere, ensuring homogeneous anchoring of S-WO₃ on HPBC. The intimate integration of S-WO₃ with HPBC generated a strong synergistic effect, resulting in abundant electroactive sites, accelerated charge transport, and enhanced electron-transfer kinetics. Differential pulse voltammetry revealed excellent sensing performance, with a limit of detection of 1.5 nM, a limit of quantification of 5.2 nM, and a sensitivity of 2.81 μA μM^–1 cm^–2. The sensor exhibited excellent repeatability, reproducibility, and selectivity, achieving recoveries of 94.6–99.91% in spiked real samples, including river water, sewage water, chicken extract, fish extract, human urine, and human blood serum. These findings highlight the synergistic contribution of S-WO₃ and HPBC, establishing S-WO₃/HPBC/GCE as a robust, cost-effective, and interference-free platform for reliable RZ monitoring in environmental, biological, and food matrices.

Systemic inflammation has been increasingly acknowledged as a pivotal factor contributing to neuropsychiatric disorders; however, therapeutic approaches specifically targeting neuroimmune interactions remain scarce. Atrial natriuretic peptide (ANP) exhibits strong anti-inflammatory effects but is limited by poor bioavailability and rapid enzymatic degradation. In this study, we developed an orally administered, gut-targeted armored nanomedicine, designated ANP-GBSA@CHI/TA, consisting of ANP-loaded albumin nanoparticles coated with graphene quantum dots and encapsulated within a multilayer shell of chitosan and tannic acid. Comprehensive physicochemical characterization confirmed the successful synthesis of core–shell nanoparticles with an average diameter of 246.8 ± 30.0 nm, demonstrating high encapsulation efficiency, excellent colloidal stability, and significant antioxidant activity, primarily attributable to the nanocarrier components. This formulation enhances intestinal retention and enables targeted delivery to inflamed tissues, as evidenced by in vivo imaging studies. In a lipopolysaccharide (LPS)-induced model of systemic inflammation model, administration of ANP-GBSA@CHI/TA markedly improved cognitive function in behavioral assays, decreased plasma concentrations of pro-inflammatory cytokines (IL-6, TNF-α), and attenuated microglial activation within the hippocampus. Mechanistic investigations revealed that the vagus nerve is indispensable for mediating these therapeutic effects, as subdiaphragmatic vagotomy abolished both the anti-inflammatory and cognitive benefits. Moreover, we demonstrated that ANP-GBSA@CHI/TA enhances hippocampal brain-derived neurotrophic factor (BDNF)/TrkB signaling, and pharmacological inhibition of this pathway significantly reverses the observed cognitive improvements and anti-inflammatory responses, highlighting its critical role in mediating treatment efficacy. Collectively, these findings indicate that this nanoplatform effectively attenuates neuroinflammation and mitigates cognitive deficits via vagus nerve-mediated modulation of the gut–brain axis immune response, thereby representing a promising therapeutic strategy for neuroinflammatory disorders.

ZnGa₂O₄:Cr³⁺ (ZGC) long-persistent luminescent (PersL) nanomaterial is a potential bioimaging contrast agent without autofluorescence. However, the existing synthetic methods such as the hydrothermal method, solid-state method, and sol–gel method are generally struggling to reconcile the contradiction between small particle size and high PersL intensity, which hinder the clinical application of ZGC. In this study, ZGC nanoparticles are prepared via an “MOFs-template-removal” method. Their hydrodynamic size distribution exhibits a peak at 160 nm. The PersL intensity reaches 5.7-fold that of its hydrothermal ZGC counterparts. Mechanisms of size control and PersL enhancement via the “MOFs-template-removal” method are thoroughly investigated using PXRD, XPS, PersL decay curves, UV–vis DRS, elemental analysis, etc. The results show that the nanoscale dimension of the MOF template, with its abundant internal pores, facilitates the formation of smaller ZGC particles. Furthermore, the copious shallow electron traps on the surface are vital for enhancing the PersL intensity of ZGC-mofs. The wide bandgap (4.88 eV) of ZGC-mofs allows for the efficient absorption of 254 nm ultraviolet light in aqueous environments, promoting the PersL emission. Additionally, the experimental results also suggest that this method holds potential for controlling the size of ZnX₂O₄-type (X = Al, In) metallic oxides, not only broadening its application scope but also inspiring the development of bioimaging materials.

Photoluminescence (PL) in monolayer (1L) MoS₂ is highly sensitive to surface chemistry and ambient exposure, which can introduce defect states that modify radiative and nonradiative pathways. Herein, we investigate the influence of long-term environmental aging (up to 1 year, ∼60% relative humidity, ∼24 °C) on the PL spectra of CVD-grown 1L MoS₂, focusing on the influence of morphology on the evolution of PL emission. While both 1L flakes and continuous films suffer from aging to different degrees, MoS₂ films show significantly higher PL reduction, broader exciton line widths, and an enhanced trion-to-exciton (A^–/A⁰) intensity ratio compared to MoS₂ flakes. This pronounced PL quenching arises from the higher grain boundary density in films, which acts as a reactive site for defect generation under ambient exposure. Complementary temporal photoresponse studies further validate this observation, revealing higher dark current and longer decay times in the aged films, consistent with increased sulfur vacancy (V_S) concentration and defect-assisted trapping. Interestingly, the aged 1L MoS₂ exhibit persistent photoconductivity and synaptic behavior, characterized by optically driven modulation of conductance and carrier relaxation. To reverse the aging-induced degradation, moderate-temperature air annealing (200–300 °C) was employed. Remarkably, the annealing leads to substantial PL recovery in both flakes and films. Spectral deconvolution reveals a narrowing and blue-shifting of the exciton emission peak, along with a reduction in the A^–/A⁰ ratio, indicating oxygen-mediated passivation of sulfur vacancies. Density functional theory further explains the trend, showing that sulfur vacancies introduce midgap states that enable nonradiative recombination, whereas oxygen incorporation suppresses these states and re-establishes radiative recombination pathways. Overall, our results connect morphology-dependent defect dynamics to macroscopic optical/electrical aging signatures and identify simple air annealing as a scalable route to heal vacancy-type defects in 1L MoS₂.

Iron-based Prussian blue analogues (Fe-PBAs) have garnered significant attention as cathode materials for sodium-ion batteries due to their high specific capacity (∼170 mAh g^–1), environmental compatibility, and cost effectiveness. However, their performance is hindered by substantial crystalline water and structural defects, which result in the insufficient electrochemical activity of Fe^LS(C). The low contribution of Fe^LS(C) to the overall capacity, compared to Fe^HS(N), results in diminished battery performance and rapid cycling degradation. This study presents an innovative synthesis strategy for low-defect, high-sodium-content nanoporous Prussian blue using an oxalic acid-assisted single-iron-source method. Subsequent heat treatment effectively removes crystalline water and introduces a controlled number of defects, further modulating the nanoporous architecture and activating the Fe^LS(C) capacity. The resulting thermally treated nanoporous material (PBA-HT) exhibits a high stable discharge capacity of 120.2 mAh g^–1, an initial Coulombic efficiency of 95.4%, and an outstanding cycling stability (70.3% capacity retention after 1000 cycles at 5 C). Density functional theory calculations reveal that heat treatment reduces the crystal field energy, thereby activating Fe^LS(C). In situ electrochemical impedance spectroscopy and galvanostatic intermittent titration technique analyses confirm a significant enhancement in diffusion kinetics, facilitated by the optimized nanoporous structure, following thermal treatment. Moreover, PBA-HT demonstrates stable operation at extreme temperatures (−20 and 50 °C), highlighting its practical potential and offering a synthesis strategy for high-performance nanoporous Prussian blue analogues.