Nanoscale Horizons最新文献

By integrating super-aligned carbon nanotube (SACNT) films with paraffin wax, an addressable optical valve composite array was created through screen printing and laser cutting. The temperature of the SACNT film can be controlled, which rapidly induces phase changes in the paraffin wax, leading to a swift change in optical transparency. The transmission spot exhibited significant differences, with a contrast degree reaching up to 0.65. At a paraffin wax surface density of 1.17 × 10^-4 g mm^-2, the rise and fall times of the transmitted optical signal across the 350-1100 nm spectrum were 155 ± 2 ms and 135 ± 11 ms, respectively, enabling rapid spatial light modulation. A prototype was fabricated, capable of dynamically displaying letters, with the crosstalk effect of the current being significantly mitigated in spatial light modulation. This rapid spatial light modulation prototype can be customized to any shape and size, and it can either be freestanding or mounted on any substrate. This innovation offers a new approach to spatial light modulation.

The increasing demand for health monitoring, voice detection, electronic skins, and human-computer interaction has accelerated the development of highly sensitive, flexible, and miniaturized pressure and acoustic sensors. Among various sensing technologies, piezoresistive sensors offer advantages such as simple fabrication, low power consumption, and broad detection ranges, making them well-suited for detecting subtle vibrations and acoustic signals. However, traditional piezoresistive materials, including metals and semiconductors, are inherently stiff and brittle, limiting their integration into wearable electronics and bio-integrated devices. To overcome these challenges, we introduce a graphene oxide (GO)/deoxyribonucleic acid (DNA) aerogel, synthesized via a self-assembly approach using pre-formed hydrogel membranes. This biodegradable and biocompatible aerogel features tunable pore sizes, low density, and excellent mechanical resilience. Upon reduction, the GO/DNA aerogel exhibits high piezoresistive sensitivity (1.74 kPa^-1) in the low-pressure range (0-130 Pa), surpassing conventional pressure sensors. Additionally, it detects acoustic signals, achieving a sensitivity of 74.4 kPa^-1, outperforming existing acoustic sensors. These findings highlight the potential of rGO/DNA aerogels as materials for next-generation wearable electronics, biomedical diagnostics, and soft robotics.

Our Emerging Investigator Series features exceptional work by early-career nanoscience and nanotechnology researchers. Read Jiang Zhou's Emerging Investigator Series article 'An ionically cross-linked composite hydrogel electrolyte based on natural biomacromolecules for sustainable zinc-ion batteries' (https://doi.org/10.1039/D4NH00243A) and read more about him in the interview below.

Two-dimensional (2D) materials, with their atomic-scale thickness, high carrier mobility, tunable wide bandgap, and excellent electrical and mechanical properties, have demonstrated vast application prospects in research on radio frequency (RF) switch devices. This review summarizes the recent advances in 2D materials for RF switch applications, focusing on the performance and mechanisms of 2D material-based RF switch devices at high frequencies, wide bandwidths, and high transmission rates. The analysis includes the design and optimization of devices based on graphene, transition metal dichalcogenides, hexagonal boron nitride, and their heterojunctions. By comparing the key performance parameters such as insertion loss, isolation, and cutoff frequency of the switches, this review reveals the influence of material selection, structural design, and defect control on device performance. Furthermore, it discusses the challenges of 2D material-based RF switches in practical applications, including material defect control, reduction of contact resistance, and the technical bottlenecks of large-scale industrial production. Finally, this review envisions future research directions, proposing potential pathways for improving device performance through heterojunction structure design, multifunctional integration, and process optimization. This study is of great significance for advancing the development of high-performance RF switches and the application of communication technologies in 6G and higher frequency bands.

Photoacoustic (PA) imaging is a burgeoning imaging modality that has a broad range of applications in the early diagnosis of cancer, detection of various diseases, and relevant scientific research. It is a non-invasive imaging modality that relies on the absorption coefficient of the imaging tissue and the injected PA-imaging contrast agent. Nevertheless, PA imaging exhibits weak imaging depth due to its exponentially decaying signal intensity with increasing tissue depth. To improve the depth and heighten the contrast of imaging, a series of PA contrast agents has been developed based on nanomaterials. In this review, we present a comprehensive overview of recent advancements in contrast agents for photoacoustic (PA) imaging, encompassing the emergence of first near-infrared region (NIR-I, 700-950 nm) PA contrast agents, second near-infrared region (NIR-II, 1000-1700 nm) PA contrast agents, and ratiometric PA contrast agents. Subsequently, the latest advances in PA image-guided cancer therapy were introduced, such as photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), and PTT-based synergistic therapy. Finally, the prospects of PA contrast agents and their biomedical applications were also discussed. This review provides a systematic summary of the development and utilization of the cutting-edge photoacoustic agents, which may inspire fresh thinking in the fabrication and application aspects of imaging agents.

Infectious diseases remain a major challenge to public health. The accurate and timely detection of pathogens responsible for these diseases is essential for controlling their spread, supporting clinical diagnosis, and enabling the application of appropriate therapies. Traditionally, the antibody-based assay has been the primary method for pathogen detection. However, recent advancements in aptamer-based technologies have initiated a transformative shift in diagnostic approaches. Aptamer-based sensors (aptasensors) are characterized by lower production costs and greater flexibility, making them compatible with various detection techniques. This broad applicability facilitates multifaceted, high-throughput applications, significantly improving the capacity to monitor and detect infectious diseases. In this review, we introduce the pathogenic mechanisms and characteristics of pathogens, provide an overview of recent advancements in the development of aptasensors for pathogen detection and highlight their versatility in identifying various infectious disease pathogens, including viruses, bacteria, parasites and other microorganisms. We systematically categorize aptasensors according to their detection mechanisms, including colorimetry, fluorescence, chemiluminescence, surface-enhanced Raman spectroscopy (SERS), surface plasmon resonance (SPR), electrochemistry and incorporation of field-effect transistors (FETs). We further demonstrate how these platforms leverage pathogen-specific biological features to achieve ultrasensitive and rapid diagnostics. Further optimization and validation of aptasensor platforms are anticipated to accelerate their clinical translation and industrialization. Advancing these innovative technologies will be crucial to meeting the growing demand for rapid, accurate and reliable pathogen detection across diverse clinical and environmental conditions, ultimately strengthening the ability to respond effectively to infectious disease threats.

Synaptic devices with integrated sensing-computing-storage functions are emerging as promising technological solutions to break the memory wall in the von Neuman architecture computing system. 2D semiconductors are ideal candidate materials for artificial synapses due to their superior electronic and optoelectronic properties. In this work, we report robust optoelectronic synapses realized on wafer-scale continuous MoSe₂ with Te-doping-induced tunable memory functions. A unique defect engineering strategy of substitutional doping of Te has been adopted to induce Se vacancies in chemical vapour deposition grown MoSe₂ films. These vacancies introduce defect states as deep trap levels in the band gap, enabling efficient charge trapping and significantly prolonging the decaying time. The presence of Te doping and Se vacancies was confirmed by PL, Raman, and XPS characterization. Ultra-high vacuum stencil lithography technique has been adopted for the fabrication of arrayed optoelectronic devices that exhibit prominent excitatory postsynaptic currents with the paired-pulse facilitation up to 197% under ultraviolet illumination. Therefore, essential synaptic behaviors like the spike-number-, spike-rate-, and spike-intensity-dependent plasticity have been demonstrated, along with the in-sensor computation application of hardware image sharpening capability. This work offers a new method of vacancy engineering in large-scale 2D semiconductors for future application in integrated neuromorphic devices.

Intracellular bacterial infections caused by antibiotic-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), pose an intractable threat to public health. Intracellular MRSA is extremely difficult to eradicate using traditional antibiotics due to the poor intracellular accumulation and drug resistance. In this work, a novel multifunctional nanoantibiotic (GZNC) was constructed using MOF-derived nanozymes loaded with botanicals for synergistic treatment of intracellular antibiotic-resistant bacterial infection. The nanoantibiotic integrated glycyrrhizinic acid (GA) into ZIF-8-derived nanozymes (ZNC), which achieved controlled release of GA, excellent photothermal effects and enhanced peroxidase-like (POD-like) activity under near-infrared (NIR) light irradiation. The nanoantibiotic showed excellent potential for in vivo and in vitro eradication of intracellular antibiotic-resistant bacteria. With the merits of NIR light-actuated botanicals/photothermal therapy (PTT)/chemodynamic therapy (CDT), the nanoantibiotic could synergistically eradicate intracellular antibiotic-resistant bacteria and alleviate associated infection, providing a promising and biologically safe pathway to address the intracellular antibiotic-resistant bacterial infection.

Our Emerging Investigator Series features exceptional work by early-career nanoscience and nanotechnology researchers. Read Yuefei Wang's Emerging Investigator Series article 'Full-color peptide-based fluorescent nanomaterials assembled under the control of amino acid doping' (https://doi.org/10.1039/D4NH00400K) and read more about him in the interview below.

High-entropy alloys (HEAs) have attracted considerable attention as promising catalysts. Despite a rapidly growing number of publications in this area, characterization of HEA electrocatalytic activity and stability remains challenging. In this paper, we report rapid and scalable microwave-shock assisted synthesis of FeCoNiCuMnCr HEA and its characterization at a single particle level. HEA particles synthesized on HOPG without additional reagents or pre-/post-treatments exhibited a significant activity toward water oxidation in 0.1 M NaOH. Individual micrometer-sized FeCoNiCuMnCr HEA particles were imaged by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) to show the uniform distribution of all six metals, and the potential dependence of the oxygen evolution reaction (OER) at its surface was probed by scanning electrochemical microscopy (SECM). Significant variations in onset potential of OER on different HEA particles were observed; however, no obvious correlation with the particle size was found. The HEA stability was confirmed by SEM/EDS imaging of the same FeCoNiCuMnCr particle after several hours of OER experiments and also by voltammetry and XRD analysis.