ACS Applied Nano Materials最新文献

Protein scaffolds play a vital role in drug delivery systems. However, few research studies have been focused on loading hydrophobic drugs on protein scaffolds in biomedical fields. Here, we report on the development of protein microspheres and nanofibers by a simple ice-templating approach and their use as scaffolds for the controlled release of hydrophobic drugs, with bovine serum albumin (BSA) as the model protein and curcumin as the model hydrophobic drug. The BSA scaffolds display the unique nanofibrous and microspherical structures. This is a surprising discovery because there has been no report on the formation of microspheres via simple ice-templating of solutions or suspensions. To further understand the formation of microspheres by this approach, lysozyme, papain, and their composites with BSA are also studied. It is speculated that nanoparticles are first formed in aqueous BSA solution, attributed to the overlapping of hydration layers and autoassembly of inner hydrophobic cores of BSA globular molecules. Nanoprecipitation and soaking evaporation approaches are then used to load curcumin into the BSA scaffolds, followed by cross-linking with glutaraldehyde vapor to improve stability in an aqueous medium. The controlled release of curcumin is demonstrated, paving the way for various hydrophobic drugs loaded into this biodegradable and nonimmunogenic protein scaffold for potential treatments of diverse diseases.

The synthesis of semiconductor nanowires (NWs) with near-infrared light-absorbing and light-emission properties is presented. Gallium (Ga)-induced vapor–liquid–solid growth is used to produce GaAs/GaInNAs/GaAs core–multishell NWs on a 2 in. Si(111) wafer using plasma-assisted molecular beam epitaxy. The GaInNAs shell consists of 11% indium (In) and varying compositions of nitrogen (N) of up to 1.9%. The NWs serve as an antireflective material, showing that the entire substrate is black. Photoluminescence measurements at room temperature validate the expansion of the operating wavelength into the near-infrared region as the N content in the NWs increases. The GaInNAs sample with 11% In and 1.2% N shows homogeneous luminescence at 1100 nm across the entire 2 in. Si substrate. The reflectance of the NW samples is low, less than 2%, and the absorption edge can be controlled by modifying the composition of In and N indicating the potential application of large-scale photoelectric conversion, such as solar cells.

In view of the increasing bacterial resistance, 2D MXenes are promising alternatives to antibiotics. However, MXene-based photothermal therapy (PTT) suffers from unsatisfactory antibacterial efficiency and heat-resistant strains. Here, we prepared a Ti₃C₂ MXene and Ag hybridized antibacterial nanocomposite [MXene/metal-polyphenol networks (MPNs)/Ag] through the in situ reduction of Ag nanoparticles on MPN wrapped MXene matrix. The use of MPNs as the reducing agents of Ag⁺ and anchoring agents of Ag nanoparticles endowed MXene/MPN/Ag with a tight immobilization capacity and improved colloidal dispersion stability of Ag nanoparticles. The pH-triggered decomposition of MPNs led to the pH-responsive release of Ag to achieve combined MXene-based PTT and Ag-mediated therapy for enhanced antibacterial efficiency. In vitro antibacterial experiments revealed its satisfactory bactericidal activities against both planktonic bacteria and bacteria in stubborn biofilms. In vivo antibacterial assays solidly confirmed its high antibacterial therapeutic efficiency, strong anti-inflammatory ability, and good biosafety. Therefore, the in situ combination of Ag nanoparticles with MXenes offers a promising microenvironment-responsive 2D bactericidal candidate for infection that could be applied in future antibacterial treatments.

The tuning of optical, morphological, and structural properties through precise control of the size/thickness of transition-metal chalcogenide is one of the key aspects for practical applications. The present study reports that the microwave-synthesized MnSe_1+xTe_1–x (MST) nanocomposite by altering Se and Te concentrations is studied for optoelectronic applications. The gradual increase in its crystallinity through MnSe and MnTe₂ crystalline phases with an increase in Se/Te ratio is confirmed by the structural study. The existence of different vibrational modes in the sample with alteration in the microstructural region is confirmed by a Raman study. The morphology study shows the nanosheet (nSh) structure as formed for the as-prepared MST samples, confirming the formation of 2D nanomaterial. The nSh thickness gradually decreased with a decrease in the Se concentration and increased Te. The reduction of the optical band gap of nSh is reflected by shifting the absorption edge to a higher wavelength regime. The refractive index values lie between 2.14 and 2.78 for different MST nSh as per theoretical calculation. The presence of various exothermal and endothermal peaks is confirmed by thermal analysis for the present sample. These materials undergo photodetection measurement, where they illustrate commendable responsivity across a range of values: 1.73, 8.88, and 28.88 nA W^–1. Additionally, these materials showcase detectivity at levels of 1.14 × 10¹⁰, 2.52 × 10¹⁰, and 3.96 × 10¹¹ Jones, respectively. The changes in different optical and structural parameters enable the material’s applicability in optoelectronic devices.

Multilayer graphene (MLG) has attracted considerable attention as an interconnect material owing to its excellent electrical and mechanical properties. Several studies on the formation of MLG on insulators have been reported; however, the process temperature and shape controllability of MLG remain challenging. In this study, we investigated the formation of MLG strips for interconnect via metal-induced layer exchange (LE). The LE of strip-patterned amorphous carbon and Ni formed {002}-oriented high-crystallinity MLG strips at low temperatures (600 °C). While voids were formed inside the strip, continuous MLG was formed at the strip edge, likely due to the remarkable atomic diffusion at the edge. Smaller widths and larger thicknesses of the MLG strip allowed us to form uniform MLG strips without voids, and an electrical conductivity of 1100 S cm^–1 was achieved. The technique developed in this study is unique because it overcomes the limitations of conventional MLG fabrication techniques and is promising for MLG interconnect applications.

The advanced oxidation process involves photocatalytic degradation, which is a propitious method of treating wastewater. However, to augment the photocatalytic activity of photocatalysts, the surface plasmon resonance (SPR) method is a highly promising candidate. Herein, we prepared bismuth (Bi) and tungsten (W)-based metal oxide (Bi₂WO₆) coupled with Ag as a semiconducting metal oxide-based plasmon resonance photocatalyst. Despite the SPR effect, the aggregation of particles lowers the efficiency of degradation. To get the better of it, morphology tuning agents and visible light-absorbing agents like CTAB (cetyltrimethylammonium bromide) were used. The prepared composite materials were characterized using sophisticated analytical instruments. The prepared materials were tested for their catalytic activity against Victoria Blue (VB) and Auramine O (AO) dyes. The composite material showed superior catalytic activity over the individual material, 97% and 98% for VB and AO, respectively. In addition, the toxicity of the byproducts (mutagenic toxicity, lethal concentration 50 (LC-50), and lethal dose (LD-50)) was estimated, and the detailed DFT interpretations were studied. Finally, a real-time agricultural application using post-treated water was conducted at the Epipremnum aureum plant.

Electrocatalytic nitrate reduction to ammonia (NRA) seriously suffers from slow kinetics and low selectivity due to its eight-electron transfer process and complex reaction intermediates. Herein, Ru-based nanotubes (NTs) were designed to enhance the electrocatalytic activity of NRA. Significantly, the metallic Ru NTs endowed remarkable ammonia (NH₃) yield rate ($v_{{\mathrm{NH}}_3}$) of 40.6 mg h^–1 mg_cat.^–1 at −1.20 V vs SCE and the highest NH₃ Faradaic efficiency (${\mathrm{FE}}_{{\mathrm{NH}}_3}$) of 98.4% at −1.10 V vs SCE under ambient conditions, which are superior to those of RuO₂ NTs ($v_{{\mathrm{NH}}_3}$: 0.52 mg h^–1 mg_cat.^–1, ${\mathrm{FE}}_{{\mathrm{NH}}_3}$: 18.2%). Both experimental and theoretical results have proved that the Ru metallic state is more beneficial to N–O bond breaking and hydrogenation than the oxidized state, improving the kinetics and selectivity of NRA.