ACS Applied Nano Materials最新文献

With the growing demand for detecting minute human signals in patients with tactile dysfunction driven by the Internet of Things (IoT) development, triboelectric nanogenerator (TENG) offers a solution for high-precision human signal monitoring. This study proposes an improved flexible TENG featuring a nanopapillary structure composed of barium zirconate titanate/strontium carbonate/polydimethylsiloxane (Sr-BZT/PDMS) for wireless monitoring of human finger bending signals. Inspired by the natural micronano architecture of lotus leaves, a biomimetic papillary structure was constructed on the surface of the negative triboelectric layer film, significantly increasing its contact area and surface roughness. Further incorporation of piezoelectric barium zirconate titanate nanoparticles and strontium carbonate enhanced the electrical output performance of the TENG through synergistic effects with a triboelectric effect. Consequently, when the Sr-BZT nanoparticle content in the biomimetic Sr-BZT/PDMS composite film reached 15 wt %, the composite film exhibited superhydrophobicity and high surface roughness (Rq = 200 nm). The corresponding TENG achieved electrical output performance of 52 V, 246 μA, and 1.7 W/m². Compared with PDMS-based TENGs, the optimized device exhibited a 49-fold increase in short-circuit current. Furthermore, the TENG maintained stable output performance after continuous operation for one month. The TENG based on this design can collect minute mechanical signals generated when a human finger bends.

To address the low energy density of polymeric capacitors, this work explores how tandem combinations of antagonistic properties can enhance energy storage. We introduce multilayer architecture integrating chemical vapor deposition (CVD)-grown ≈2 nm hexagonal boron nitride (hBN) and graphene with ferroelectric polyvinylidene fluoride (PVDF) and linear polyetherimide (PEI) layers to suppress leakage paths, reduce loss, and promote Maxwell–Wagner–Sillars polarization. Raman spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and plasma focused ion beam (PFIB) analyses confirm robust material integration. For the tandem device, E_BD ≈600 V/μm, while individual layers show lower values (PVDF|Graphene (Gr)|PVDF ≈ 50 V/μm and PEI|hBN|PEI ≈ 275 V/μm), yielding an overall ≈6000% enhancement and demonstrating the effectiveness of the 2D multilayer design.

A simple ultraviolet (UV) radiation-assisted chemical route has been successfully employed to grow tin oxide (SnO₂) nanoparticles onto MWCNTs to form SnO₂-MWCNT nanocomposite. Structural, surface morphological, functional, and elemental techniques have been performed to analyze the nanocomposite. The synthesized nanocomposite has been employed not only as a supercapacitive electrode but also to configure a large area (10 cm × 4 cm) solid-state supercapacitor device. Electrochemical investigation of the electrodes yields a specific capacitance of 122.14 F/g (areal 103.8 mF/cm²) at 5 mV/s with a stable voltage window of 1 V along with capacitive retention of 101% at 3000 cyclic voltammetry (CV) cycles. Interestingly, the solid-state symmetric device delivered a specific capacitance of 36.89 F/g (areal 31.3 mF/cm²) at 5 mV/s with a superior capacitive retention of 90% at 3000 CV cycles with a wider voltage window of 2 V. Two devices in series and parallel combinations have been thoroughly assessed using CV, galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS), and phase angle analysis. Interestingly, the single solid-state device has been successfully employed to power three LED panels and a small fan, whereas two devices connected in series and parallel have been used to power an LED panel consisting of 1150 LEDs, along with a series device powering a large fan to showcase the prototype nature.

The conservation of heritage documents and books requires the use of appropriate materials that ensure effective and durable restoration. In this study, innovative transparent and mechanically robust nanopapers were developed using bacterial nanocellulose (BNC) combined with various commercial cellulose ethers. The developed nanopapers were thoroughly characterized in terms of morphology, porosity, optical properties, barrier performance, mechanical properties, and accelerated aging behavior. The results showed that the incorporation of cellulose ethers significantly enhanced the transparency, barrier properties, and mechanical performance of the nanopapers. Moreover, accelerated aging tests demonstrated excellent chromatic stability. The nanopapers developed were used in the restoration of 18th and 19th century documents, demonstrating their potential as innovative conservation materials. BNC/cellulose ether nanopapers emerge as promising alternatives to conventional restoration papers, offering also superior performance compared to pure BNC nanopapers.

Gastric ulcers, caused by factors such as H. pylori infection and NSAID misuse, are characterized by mucosal barrier erosion and severe complications. Current therapeutic approaches employing proton pump inhibitors, H₂-receptor antagonists, antibiotics, and antacids face challenges, including reduced bone density, rising antibiotic resistance, and poor drug targeting. Here, we developed a dual-targeting oral nanodelivery system (CFLTM) with a size range of 100 nm to 450 nm and an average size of 335 nm using a cascade-targeting strategy. CFLTM combines folic acid and chondroitin sulfate to enhance targeting precision in an acidic gastric environment. It is loaded with tannic acid and magnolol for anti-inflammatory and antioxidant effects. The study shows that CFLTM exhibits exceptional targeting efficiency, with its dual-targeting uptake capability demonstrating a significant 1.21-fold enhancement compared to single-targeting systems. This enables rapid and precise localization to gastric ulcer sites while reducing oxidative stress and inflammation through modulation of key biomarkers. Using a green aqueous synthesis process, CFLTM achieves low energy consumption and high encapsulation efficiency. This innovative system shifts gastric ulcer treatment from passive acid suppression to active tissue repair, providing a new therapeutic approach and a platform for treating other digestive diseases.

Detection of disease biomarkers at ultratrace concentrations remains a major bottleneck in molecular diagnostics, restricted by the intrinsic limitations of aptamer affinity, the scarcity of analyte molecules, and insufficient signal amplification strategies. In this work, we report a surface-enhanced Raman scattering (SERS) sandwich assay supported by theoretical basis that addresses these challenges by integrating aptamers, nanomeshes, and reporter nanoprobes. The resulting platform enables reliable detection of biomarkers in the attomolar range, representing a significant advance in sensitivity compared to conventional aptamer-SERS assays. The aptamer-nanomesh design demonstrated robust performance in detecting rotein biomarkers in human serum, maintaining high recovery rates even in the presence of complex matrix interferences that typically hinder ultrasensitive measurements. Beyond a single target, the approach was extended to multiple protein targets, where each analyte produced distinct and quantifiable Raman signatures, underscoring the assay’s versatility and potential for multiplexing applications. By addressing the fundamental limitations of natural aptamer-target interactions and enhancing molecular signal readouts, this study advances aptamer-SERS biosensing toward practical translational applications.

Lead-free perovskites are ecofriendly and highly engineered materials of great interest to researchers for their versatile crystal structure and tunable composition, which contribute to exceptional electronic, optical, and catalytic properties. Herein, we have synthesized two different lead-free cobalt halide perovskites (CHPs), 0D-Cs₄Co₂Cl₆ and 2D-Cs₄Co₂Cl₈ nanocrystals, using a simple ultrasonication method (US) and a modified ligand-assisted reprecipitation method (LARP), respectively. In the LARP method, interestingly, a polar solvent (methanol) was employed here with a mixture of coordinating ligands such as oleic acid (OA) and oleylamine (OLA). The crystal formation and morphology of these CHP nanocrystals were confirmed by single-crystal X-ray diffraction (Sc-XRD) and high-resolution transmission electron microscopy (HR-TEM) analyses, respectively. Furthermore, these CHPs exhibited luminescent properties with a variable quantum yield (QY) of 6.11% for 0D- CHP and a QY of 7.23% for 2D- CHP, respectively. These characteristics enable their evaluation in bioimaging and apoptosis assays using HT-29 human colon carcinoma cells. Furthermore, as versatile materials, these two CHP nanocrystals were also investigated for the electrochemical determination of dopamine (DA), a neurotransmitter whose depletion is directly implicated in Parkinson’s disease, with a comparable limit of detection (LOD) of 0.76 μM (US) and 1.2 μM (LARP), respectively.

In recent years, metallic nanostructures have become essential in biosensing due to their unique optical properties, making them excellent optical transducers. Among various fabrication techniques, solid-state dewetting of nanofilms provides a fast and cost-effective method for creating large-scale plasmonic arrays. However, the interaction between the supporting substrate and the metal nanostructure plays a critical role in the localized surface plasmon resonance (LSPR) sensitivity, influencing the local refractive index (RI) of the nanostructure. In this study, we demonstrate the development of hybrid Au–Si₃N₄ nanostructures that exhibit enhanced localized surface plasmon resonance (LSPR) sensitivity and an exceptionally low detection limit (LOD) for streptavidin in the subfemtomolar range. To achieve even greater performance, the Si₃N₄ substrate undergoes an etching process, which further refines the features of the nanostructures, leading to improved sensing capabilities. This enhancement, achieved through substrate etching, plays a crucial role in maximizing the sensitivity and effectiveness of hybrid nanostructures for advanced biosensing applications. The large-scale fabrication process of hybrid nanostructures enables remarkable performance in refractive index (RI) sensitivity. Indeed, the obtained nanostructures display a high average RI sensitivity, making them highly effective for biomedical sensing applications where detecting changes in RI is crucial. The results of this work demonstrate that combining hybrid plasmonic and dielectric materials can significantly enhance sensing performance and, when integrated into silicon-based optoelectronic devices, expand their use in advanced biosensing technologies.

Gold nanobipyramids (GNBPs) were investigated as near-infrared contrast agents for the optical coherence tomography (OCT) tracking of human corneal stromal stem cells (CSSCs). GNBPs with various longitudinal localized surface plasmon resonance peaks were synthesized, and the variant with a peak at 855 nm (GNBPs-1), closest to the central wavelength of the OCT system, exhibited an optimal OCT signal enhancement. To improve stability and biocompatibility, GNBPs-1 were PEGylated. In vitro studies confirmed that PEGylated GNBPs were nontoxic to human CSSCs at concentrations up to 1.6 × 10⁷ particles per cell. At a labeling concentration of 2 × 10⁶ particles per cell, the OCT signal intensity increased by approximately 3-fold and remained detectable for at least 48 h. The OCT signal intensity and the number of detectable cells correlated closely with cell status upon GNBP-labeling, indicating enhanced tracking of intact transplanted cells. Ex vivo experiments using rabbit corneas demonstrated that GNBP-labeled CSSCs embedded in hydrogel exhibited significantly enhanced OCT contrast compared to unlabeled cells, with signal persistence for more than 7 days. Overall, these results identify GNBPs as effective, nontoxic, and long-lasting OCT contrast agents for donor CSSC tracking, highlighting their potential for use in corneal regenerative therapies.

The manipulation of photoluminescence (PL) in two-dimensional (2D) materials presents a promising approach for the development of compact and tunable nanoscale light sources. Although monolayer transition metal dichalcogenides (TMDCs) exhibit strong excitonic emission owing to their direct bandgap, multilayer TMDCs generally experience reduced PL efficiency due to their indirect band structure. Here, we demonstrate that nanostructured WS₂ deposited on an Ag film exhibits markedly enhanced indirect PL emission, facilitated by metal film-assisted near-field enhancement and exciton-resonant excitation. Through systematic comparison of WS₂ nanoparticles on Ag and indium tin oxide (ITO) film under varying excitation wavelengths and powers, we show that the Ag substrate enhances PL intensity via metal film-induced field concentration, which is about 27 times stronger than that on the ITO film with the same excitation condition. Numerical simulations corroborate that the observed enhancement results from the enhancement effects of electric field localization and exciton-resonant absorption. Moreover, high-energy excitation induces additional PL peaks, which are attributed to hot carrier relaxation and direct transition phenomena. These findings provide fundamental insights into exciton dynamics within multilayer TMDC nanostructures and propose a scalable strategy for engineering their optical responses through hybrid platforms, thereby establishing a foundation for future applications in nonlinear optics, quantum photonics, and integrated 2D material-based optoelectronic devices.