ACS Applied Nano Materials最新文献

This study presents a highly sustainable nanocomposite platform for dual applications in both photocatalysis and sensing. The nanomaterial is synthesized via a green process using natural, readily available components, including halloysite nanotubes (HNTs), glutathione (GSH), and xanthopterin, utilizing copper ions (Cu¹⁺) as the catalytically active species. The synthesis, which exclusively uses green solvents like tetrahydropyran (THP) and water, involves functionalizing HNTs with (3-aminopropyl)triethoxysilane (APTES), followed by the attachment of GSH as a chelating agent for Cu¹⁺. Finally, xanthopterin is loaded to act as a light-harvesting antenna. Fourier-transform infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA) confirmed the successful functionalization and composition. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis validated the material’s morphology and elemental composition. The resulting nanocomposite, HNT-NH₂-GSH-Cu¹⁺-X, demonstrated a remarkable synergistic effect, achieving a CO₂ conversion of 42.2% and a high (86.1%) CH₄ selectivity. Furthermore, the HNT-GSH-Cu²⁺ nanocomposite exhibited excellent electrochemical sensing capabilities for bisphenol A, with a low limit of detection (LOD) of 0.022 μM and a high sensitivity of 5.098 μA μM^–1·cm^–2. The work successfully demonstrates the creation of a sustainable, multifunctional nanomaterial that addresses critical environmental challenges by combining efficient solar fuel production with highly sensitive pollutant detection.

We report a high-performance thermochromic VO₂-based coating prepared on standard glass at a low substrate temperature of 350 °C without opening the vacuum chamber to the atmosphere. It is formed by four layers of W-doped VO₂ nanoparticles dispersed in the SiO₂ matrix. The coating exhibits a transition temperature of 33 °C with an integral luminous transmittance of 65.4% (low-temperature state) and 60.1% (high-temperature state), and a modulation of the solar energy transmittance of 15.3%. Such a combination of properties, together with the low temperature during preparation, fulfills the requirements for large-scale implementation on building glass and has not been reported yet.

Energy conversion processes involving the electrochemical reduction of small molecules such as N₂ and CO₂ using renewable energy sources hold great promise for the sustainable development of mankind. N₂ reduction leads to NH₃, a key chemical used in fertilizers, and the CO₂ reduction results in the production of industrially relevant value-added chemicals with a decrease in the carbon footprint. However, the lack of suitable electrocatalysts with low overpotentials and high selectivity due to the inert nature of N₂ and CO₂ molecules is central to the development of next-generation technologies for these complicated and kinetically slow energy conversion processes. Recently, layered two-dimensional metal carbides and nitrides, collectively called MXenes, have shown considerable ability for driving a wide spectrum of chemical transformations owing to their excellent properties such as high surface area, tunable surface chemistry, and excellent electrical conductivity. Moreover, the interfacial chemistry of these layered materials can be easily engineered to tune their activity for driving complex electrocatalytic processes. Accordingly, this review provides a comprehensive overview of the latest advances made in understanding the nitrogen reduction reaction (NRR) and CO₂ reduction reaction (CO₂RR) activity of MXenes from an electronic-structure-driven and mechanistic perspective, with a primary emphasis on insights derived from density functional theory. We primarily highlight the intricate role of surface functionalization, mixed termination, defect chemistry, and single atom engineering in modulating reaction pathways, selectivity, and kinetic barriers for NRR and CO₂RR. In addition to thermodynamic screening based on limiting potentials, recent progress in microkinetic modeling and experimentally benchmarked performance metrics is critically discussed to bridge the gap between theoretical predictions and experimental observations. Furthermore, a comprehensive analysis of the reaction mechanism of NRR and CO₂RR to identify the key scaling relationships between the limiting potential, electronic properties, and adsorption energy of intermediates is discussed in detail to facilitate the catalyst design for these energy conversion processes. Finally, the challenges and opportunities associated with MXene-based electrocatalysts─including stability, surface reconstruction, suppression of competing hydrogen evolution reaction, and scalable synthesis─are discussed, along with a forward-looking outlook on emerging strategies such as operando spectroscopy, data-driven catalyst discovery, multiscale modeling, and alternative 2D materials for advancing NRR and CO₂RR technologies.

In this study, a dual-mode immunoassay that combines terahertz (THz) and surface-enhanced Raman scattering (SERS) techniques was proposed for the detection of tumor markers (TMs). The biosensor employs a polarization-independent metamaterial (MM) composed of a planar array of cross-shaped four-split resonant rings as the THz resonator and SERS substrate. The capture antibody (Ab2) immobilized on the metasurface enables the specific recognition of the target TM. Simultaneously, gold nanoparticles (AuNPs) are conjugated with a label antibody (Ab1) and attached to the Raman reporter molecule 6-carboxy-X-rhodamine (6-ROX) to fabricate a double-signal nanoprobe (AuNPs-Ab1@ROX). In the presence of the target, the nanoprobe binds to form sandwich-type immune complexes on the metasurface via antigen–antibody interactions. THz detection was performed via transmission THz time-domain spectroscopy (THz-TDS), and SERS signals were collected with a 633 nm excitation laser. The constructed dual-mode method exhibited excellent selectivity and sensitivity for the detection of the three TMs, and the limits of detection (LODs) in the THz and SERS modes were as follows: CA199 ( 0.28, and 0.26 U/mL), CA242 (0.49 and 0.13 U/mL), and POSTN (0.25 and 0.48 ng/mL). Additionally, the dual-mode immunoassay demonstrated effectiveness in quantifying CA199, CA242, and POSTN in spiked serum samples with favorable recovery. These results confirm that the dual-mode immunoassay we propose can detect multiple TMs with high sensitivity and thus holds promising application prospects in the combined analysis of TMs and early cancer diagnosis.

With the progressive depletion of petroleum resources and the worsening greenhouse effect, the demand for sustainable materials has become increasingly urgent. In this study, a composite film was fabricated using waste tobacco stems as the raw material by integrating the TEMPO oxidation process with the in situ growth of metal–organic frameworks (MOFs) and subsequent Ca²⁺ cross-linking. The incorporation of ZIF-8 significantly enhanced the film’s thermal stability, hydrophobicity, and water vapor barrier performance. Compared with pure cellulose nanofiber (CNF), the ZIF-8-loaded composite film exhibited a markedly higher water contact angle (68.2°) and tensile strength (130.54 MPa). The structural characteristics of the films were comprehensively analyzed using FTIR, XRD, and XPS. Moreover, the composite film demonstrated outstanding antibacterial activity, with the addition of Ca²⁺ facilitating the sustained release of antibacterial agents. The film effectively extended the postharvest storage life of grapes. Owing to its multifunctional properties, the ZIF-8/CNF-Ca composite film shows great potential as a biodegradable alternative to conventional plastic packaging materials.

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that affects motor neurons. Mutations in superoxide dismutase 1 (SOD1) cause protein misfolding, amyloid accumulation, and an increase in reactive oxygen species (ROS), which contribute to the disease’s progression. There is currently no cure, and our limited understanding of ALS makes it difficult to develop effective treatments. Gold nanoparticles (GNPs) can cross the blood–brain barrier and are becoming promising tools for drug delivery. Lipoic acid (LA) fights oxidative stress but is poorly absorbed and unstable. In this study, we developed LA-conjugated GNPs (GNPs–LA), which inhibited SOD1 aggregation, reduced ROS production, and minimized cellular damage. The GNPs–LA system showed excellent biocompatibility, offering therapeutic potential for ALS treatment.

Small-sized platinum nanoparticles (Pt NPs) exhibit high peroxidase-like activity but suffer from self-agglomeration and poor stability. To solve this problem, using porous aminophenol formaldehyde resin (APF) microspheres as a support, a sulfhydryl-functional Pt NPs-based hybrid nanozyme (APF@Pt NPs) with excellent peroxidase-like activity was designed by anchoring Pt NPs on the surface of APF. High specific surface area and abundant active groups of APF microspheres facilitate the uniform distribution of Pt NPs. This design not only enhances the dispersibility of Pt NPs to prevent aggregation but also exposes more active sites─key factors that contribute to the improved catalytic performance of APF@Pt NPs. Using APF@Pt NPs as a recognition element, a sensitive colorimetric method was developed for mercury ion (Hg²⁺) detection through specific inhibition of Hg²⁺ on the peroxidase activity of APF@Pt NPs. This sensor exhibited good linearity (R² = 0.952) in the range of 0–3.125 μM. The limit of detection (LOD) was as low as 0.096 μM, along with satisfactory recoveries of 98–115% and relative standard deviation (RSD) < 3.75% in real water. Integrated with a hydrogel-sensor and smartphone APP, a real-time and visual intelligent sensing platform enabled a rapid qualitative and quantitative analysis of Hg²⁺ by RGB analysis in environmental samples. These findings illustrate that the application of APF@Pt NPs provides an effective support-engineered strategy to enhance and regulate the peroxidase-like activity and stability of small-sized Pt NPs. This also presents a multifunctional sensing platform for on-site and real-time monitoring of heavy metals in complex environmental samples.

Electrohydrodynamic printing enables high-resolution fabrication via nanoscale charged droplets. However, droplet trajectories are sensitive to electric field distortions over nonuniform substrates like coplanar electrodes (CEs). We systematically investigated passive droplet deflection during nanoscale printing on CEs through simulations and experiments. The electrode gap length and nozzle position are identified as key governing factors. A quantitative model relating these parameters to the deposition offset enables trajectory prediction. By applying adaptive speed and dynamic voltage control, continuous conductive silver nanocrystal lines with a 61.1 nm width are fabricated. This work provides a framework for enhancing printing precision in microelectronics and digital manufacturing.

Carbon dots (CDs) are recognized for their excellent features, including chemical versatility, high biocompatibility, water solubility, low toxicity, minimal photobleaching, and efficient cellular internalization. The conjugation of porphyrins with CDs has emerged as a promising strategy to address the low solubility of these macrocycles in aqueous media and their lack of specificity for cancer cells, thereby expanding their potential as photosensitizers, particularly for photodynamic therapy. In this study, CDs synthesized from citric acid and tris(hydroxymethyl)aminomethane were successfully conjugated via covalent bonding to readily available 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, affording a nanohybrid TAPP-Catris. The success of covalent functionalization was confirmed using Fourier Transform Infrared Spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Photochemical characterization confirmed that the nanohybrid effectively generated the reactive cytotoxic species, singlet oxygen (¹O₂). Biological assays on triple-negative breast cancer HCC1806 and skin malignant melanoma A375 cell lines revealed that TAPP-Catris exhibits high cytotoxicity under irradiation with filtered light (cutoff >560 nm), with IC₅₀ of 3.22 and 3.88 μM respectively. May-Grünwald Giemsa staining confirmed that cell death was mediated by apoptosis. To the best of our knowledge, this porphyrin-based nanohybrid exhibits the highest photodynamic therapeutic activity, for these cell lines.

The skin is the largest organ of the body, and wounds caused by trauma, surgery, and extensive burns are a source of bacterial infection and pose a significant public health concern. Additionally, the excessive use of antibiotics for bacterial infections significantly reduces the susceptibility of bacterial strains to treatment, ultimately leading to the emergence of antimicrobial resistance (AMR). A dressing protects the wound, adsorbs exudate, shortens the inflammatory process, and promotes healing. Recently, natural or bioinspired surfaces covered with nanopillars have been reported to exhibit antibacterial properties by physically destroying bacterial cells, thereby circumventing the challenges posed by traditional antibacterial agents. These antibacterial nanopillars were also shown to be effective against bacteria that display AMR, but they did not increase bacterial drug resistance. However, it was found that dead bacteria and debris easily accumulate on the nanostructures, degrading their antibacterial properties and ultimately eliminating the germicidal performance of the surface. In this study, gold was deposited on the surface of poly(vinyl alcohol) (PVA)/poly(methacrylic acid) (poly(MAAc)) nanopillars; the nanopillars were modified by temperature-responsive poly(N-isopropylacrylamide) (poly(NIPAAm)) with a thiol group (–SH) at the chain end by utilizing the interaction between –SH groups and gold. Owing to the modification with poly(NIPAAm)-SH, the surface properties of the modified nanopillars were controlled by changing the temperature and salt concentration. At temperatures above the cloud point (CP), the poly(NIPAAm)-SH on the nanopillar surface became hydrophobic, capturing bacteria and exhibiting antibacterial properties. By contrast, at temperatures below the CP, the poly(NIPAAm)-SH on the nanopillar surface became hydrophilic, enabling the removal of the adsorbed bacteria.