ACS Applied Nano Materials最新文献

Bacterial-infected wounds present a significant clinical challenge due to persistent bacterial infection, elevated reactive oxygen species (ROS) levels, and a complex inflammatory microenvironment, all of which impede the healing process. Vascular network damage further exacerbates these issues by disrupting the metabolic circulation, intensifying hypoxia, and promoting ROS accumulation. Conventional single-function wound dressings are inadequate to address the multifaceted biological requirements for effective wound healing. In this study, we designed a nanocomposite hydrogel (AM/AG-ZIF-8@Ba) composed of acrylamide (AM)/agarose (AG) and ZIF-8 nanoparticles loaded with baicalein (Ba) as an advanced wound dressing. The AM/AG-ZIF-8@Ba hydrogel demonstrated exceptional mechanical properties, superior moisture retention capabilities, and potent antibacterial activity. AM/AG-ZIF-8@Ba can release active substance Ba slowly for a long period of time under physiological environment, and the cumulative release ratio of Ba reaches 61.58% in 96 h, which is able to play the role of scavenging ROS continuously (scavenging ratio of 67.84 ± 1.42%). Concurrently, Zn²⁺, released by ZIF-8 degradation, has been shown to synergise with Ba, thereby promoting vascular regeneration and accelerating wound healing. In vivo experiments revealed that AM/AG-ZIF-8@Ba significantly accelerated wound healing, achieving a healing ratio of 92.57 ± 4.07% by day 14, which was significantly better than that of the control group (65.22 ± 4.67%). Histological analysis confirmed that AM/AG-ZIF-8@Ba effectively promoted neovascularization and collagen deposition while mitigating inflammatory responses (demonstrating a 63.78% reduction in pro-inflammatory cytokine IL-6 and a 99.97% increase in anti-inflammatory cytokine IL-10 compared to controls), highlighting the hydrogel’s regenerative potential. Therefore, AM/AG-ZIF-8@Ba, integrating antibacterial, antioxidant, and anti-inflammatory functions, represents a comprehensive and innovative solution for treating complex bacterial infection wounds, offering significant promise for advancing wound care and tissue regeneration.

The integration of single-layer transition metal dichalcogenides (TMDCs) in nanoscale field-effect transistor devices requires the deposition of a high dielectric constant (high-κ) material to act as the gate dielectric. Traditional thermal atomic layer deposition (ALD) is commonly used to deposit dielectrics on three-dimensional substrates, but ALD of high-κ materials on monolayer TMDCs is more challenging. Thermal ALD with water (H₂O) co-reactant often results in incomplete and nonuniform dielectric growth on atomically thin TMDCs, owing to a chemically inert basal plane. The development of alternative ALD processes for the realization of dielectric layers on monolayer TMDCs is therefore important. Here, we study oxygen (O₂) plasma and ozone (O₃) as co-reactants for the ALD of aluminum oxide (Al₂O₃) and hafnium dioxide (HfO₂) on monolayer molybdenum disulfide (1L MoS₂) films. By employing a robust characterization process that combines atomic force microscopy, Raman/photoluminescence spectroscopy, and X-ray photoelectron spectroscopy, we reveal growth of high-κ dielectrics by plasma-enhanced ALD with O₂ plasma oxidant damages the underlying 1L MoS₂ via oxidation to molybdenum trioxide (MoO₃). No significant deleterious oxidation to MoO₃ is observed following O₃-based deposition on 1L MoS₂, and we demonstrate the growth of HfO₂ via thermal ALD with O₃ co-reactant. This work reveals the impact of ALD processes on 1L MoS₂ during the growth of high-κ dielectrics, highlighting O₃-based thermal ALD as a potential route for the integration of dielectric layers on 1L MoS₂ for nanoscale optoelectronic device fabrication.

As an emerging 2D-layered semiconductor material, the Bi₂O₂Se nanosheet has shown great application potential in the field of electronics and optoelectronics due to its high carrier mobility, superior air stability, and tunable bandgap. However, the mechanism of controllable synthesis of Bi₂O₂Se nanosheets is still unclear, and further basic research and applications are urgently needed in the field of photovoltaics. In this paper, Bi₂O₂Se nanosheets were prepared based on the “dual-source independent control” method, and photodetectors were demonstrated on Si/SiO₂. The device has a mobility of 258.6 cm² V^–1 s^–1, responsivity of 8030 A/W at 532 nm (0.32 mW/cm²), and detectivity of 1.972 × 10¹¹ Jones, and the detector obtains highly stable and recoverable properties with multiple laser switches. The modulation mechanism of Bi₂O₂Se-based photodetectors is then explored based on the I–V characteristics of photodetectors and photoconductivity effect solutions.

In this investigation, we have developed a highly efficient and robust electrode nanocomposite tailored for the electrochemical sensing of 4-nitroaniline (4-NA), a hazardous pollutant. We synthesized a three-dimensional flower-like molybdenum disulfide (MoS₂) embedded tungsten carbide (WC) nanocomposite utilizing a straightforward ultrasonic technique. This nanocomposite was integrated onto a screen-printed carbon electrode (SPCE) and optimized for electrochemical detection. Under these optimal conditions, the MoS₂/WC nanocomposite demonstrates remarkable analytical performance for 4-NA detection, characterized by two distinguishable linear concentration ranges of 2–458 μM and 458–1288 μM. The sensor exhibits a sensitivity of 1.38 μA μM^–1 cm^–2 and a low detection limit of 0.034 μM, highlighting its potential for effective real-time monitoring of 4-NA in environmental samples. The enhanced performance of the MoS₂/WC/SPCE can be attributed to the synergistic effect of individual MoS₂ (large specific surface area, unique structural characteristics) and WC (high conductivity, increased number of active surface sites, and high stability). The MoS₂/WC nanocomposite demonstrates superior electrocatalytic performance for the reduction of 4-NA in neutral electrolytes compared to previously reported electrocatalysts. Moreover, the MoS₂/WC-modified SPCE shows remarkable selectivity and good reproducibility in detecting 4-NA. This innovative approach holds significant promise for advancing environmental application outcomes for real-time sensing applications.

With the increasing incidence of skin cancers each year, there is growing concern regarding ultraviolet (UV) radiation protection. However, titanium dioxide (TiO₂), as a commonly used physical sunscreen agent, has certain photocatalytic activity, which can generate a large amount of reactive oxygen species (ROS), thus posing potential skin toxicity risks. Incorporating organic molecules with free radical scavenging ability to modify TiO₂ can effectively improve the UV protection performance. In this study, the PC–PDA@TiO₂ composite nanoparticles were successfully prepared by coupling the biomolecules phycocyanin (PC) and polydopamine (PDA) to the surface of TiO₂ nanoparticles using a simple spontaneous oxidation polymerization method. Characterization methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analyses demonstrated that the PC–PDA@TiO₂ composite nanoparticles uniformly coated with a PC–PDA composite nanolayer have been successfully prepared. The UV–vis diffuse reflectance spectroscopy results and electron spin resonance (ESR) tests showed that the PC–PDA composite nanolayer significantly increased the UV absorption capacity of the composite nanoparticles and reduced the concentration of free radicals through the synergistic effect of PC and PDA. Furthermore, in vitro toxicity assessment and in vivo UV protection efficiency tests showed no significant cytotoxicity and high UV protection efficiency of the PC–PDA@TiO₂ composite nanoparticles. These findings suggest that the biomacromolecule PC shows great promise as a safer material for sunscreen products to enhance their efficacy.

Nanotechnology-based approaches are increasingly recognized in cancer biology owing to their substantial impact on various tumor cells. Nanoparticles (NPs) can serve as carriers of nanoscale drug cargos and traverse neuronal cell membranes within the nasal cavity, thereby providing an effective means to bypass the blood–brain barrier, which otherwise limits the delivery of therapeutic agents to the brain. In this study, we investigated the feasibility of axonal trans-synaptic transport of MRI-sensitive magnetic MnFe₂O₄ (MFO) NPs from the nasal cavity to intracranially xenotransplanted glioblastoma in SCID mice. Using T1-weighted MRI, we mapped the distribution of MFO NPs and found that they accumulated in the tumor only when the glioblastoma was in direct contact with olfactory-system structures involved in nose-to-brain transport. Additionally, inhibition of axonal transport nearly abrogated the NP delivery to the tumor. Notably, olfactory-system stimulations via odor presentation significantly enhanced the nose-to-glioblastoma transport of MFO NPs. Thus, although neuronal interactions with cancer cells have detrimental effects, these interactions may also expand opportunities for targeted drug delivery during glioblastoma treatment.

Piezoresistive sensors are widely used in strain and pressure sensors needed in a range of industrial, automotive, aerospace, consumer, and other applications. Aerogel-based sensors provide the advantages of lightweight, large contact area, and high sensitivity desired in practice. While silica, metal oxide, and metallic aerogel-based sensors demonstrate these advantages, wearable devices demand flexibility in addition to the above attributes, thus creating the need for investigating alternate materials. Here, we present a PDMS-coated MXene nanoribbon-PEDOT:PSS composite aerogel-based piezoresistive sensor and evaluate its performance in response to various body motions. The as-fabricated composite aerogel-based strain sensor exhibits a gauge factor of 2.63, which corresponds to a compressive strain of 14.9%. The sensing performance of the nanocomposite aerogel-based sensor is driven by the “disconnect–connect mechanism”, involving the breakdown and reformation of the conductive network in response to applied or released strain or pressure. Furthermore, the sensor exhibits hydrophobic properties, as demonstrated by a water contact angle of 113.8°. Interestingly, the sensor remains stable even after 2500 cycles of compression. In addition, the fabricated aerogel exhibits great potential as an effective thermal insulator. These results are important for the development of MXene aerogel-based lightweight and wearable sensors for health monitoring and other futuristic applications.

The industrialization process accelerates more and more kinds of volatile gas, with serious threats to the environment or human health having received great attention. Therefore, rapid real-time monitoring of harmful gases is urgently needed. This study investigated the gas-sensitive properties of an aramid nanofiber/MXene nanosheet (ANF/MXene) composite aerogel for detecting ammonia (NH₃) at room temperature. Initially, two-dimensional (2D) MXene nanosheets were synthesized by removing Al atoms from Ti₃AlC₂ (MAX phase), which were then combined with ANF to produce a porous composite aerogel through freeze-drying. At room temperature, the response value of the ANF/MXene aerogel to 50 ppm of NH₃ was approximately 4.96%, with a rapid recovery time (28 s), and remained stable even after 10 cycles. Additionally, the aerogel exhibited excellent long-term stability, lasting up to 45 days. Moreover, the ANF/MXene composite aerogel showed outstanding flexibility and flame retardancy, and it could bend and recover at low temperatures (−196 °C). As a result, the good gas-sensitive properties and stable mechanical properties enable the ANF/MXene aerogel to be suitable for flexible wearable sensor devices toward different environmental conditions in the future.

Semiconductor superlattice nanowires are promising candidates for multifunctional optoelectronic devices due to their periodic structure and compositional modulation. However, the realization of superlattice nanowires for multiple microcavity nanolasers remains challenging. Here, we report a rational strategy for the synthesis of CdS/Sn superlattice nanowires by a chemical vapor deposition (CVD) approach. Structural characterization reveals periodic CdS and Sn segments along the nanowire axis. Spatially resolved microphotoluminescence measurements confirm multiple microcavities between the adjacent Sn nodes in a single nanowire. Additionally, a room-temperature single-mode laser is clearly observed from these superlattice nanowires, which shows a strong stimulated emission with a high-quality factor (∼1218). These findings suggest that the prepared CdS/Sn superlattice nanowires provide a versatile platform for light–matter interaction studies and can be used as an excellent optical gain medium for high-quality factor lasers.

Modifications of natural fabric’s surfaces are typically achieved by chemically or physically incorporating functional agents (water-repellent and antimicrobial properties) into the fabric’s fibers. Regarding environmental concerns and health safety, a treatment process employing a water-applicable or emulsion form is preferred in manufacturing hygiene-grade products, e.g., face masks. In this study, a water-based dispersion of alkyl ketene dimer (AKD) nanoparticles (a hydrophobic agent) was fabricated by a facile oil-in-water emulsion with an ultrasonication-assisted process, followed by solvent evaporation. Aiming to stabilize AKD emulsion and provide antimicrobial properties, a phosphatidylcholine (PC) molecule containing a choline group and a phosphate moiety was selected as a surfactant. The obtained water-based AKD nanoparticles showed high stability and were monodispersed with an average size of 182.5 ± 1.0 nm. The AKD nanoparticle dispersion was then applied to the cotton fabric’s surfaces by ultrasonic spraying. Fourier transform infrared spectra indicated the chemical reactions between AKD and hydroxyl groups of the cotton fabric’s cellulose structure. This enhanced the hydrophobicity of the fabrics with a water contact angle of 137 ± 3°. SEM-EDX results revealed a rough surface with a good distribution of C, O, and P elements, reflecting that AKD molecules fully cover the surface of the cotton fabrics. After 20 washing cycles, including UV exposure, the treated fabrics still showed high water repellency, indicating high durability. Moreover, the treated fabric showed an efficiency against both Gram-positive and Gram-negative bacteria, S. aureus and E. coli, of 94.7 and 70.2%, respectively. The results demonstrate that the treatment with water-based AKD nanoparticles effectively imparted the cotton fabric with durable water-resistant and antimicrobial properties due to the chemical bonding formed between fabric fiber and AKD molecules and the synergistic effect of the hydrophobicity of AKD and charged groups of PC surfactant.