Nanoscale Horizons最新文献

Photochromic materials with rapid response and high stability are essential for progressive anti-counterfeiting and secure information encryption technologies. Herein, we report a Förster resonance energy transfer (FRET)-assisted strategy to boost the photochromic properties of highly crystalline C₃N₅ nanosheets (HC-C₃N₅) by integrating carbon dots (CDs). The incorporation of CDs significantly increased light absorption, fluorescence intensity, and energy transfer efficiency, leading to an ultrafast and reversible color transition from dark yellow to green under UV irradiation, with complete recovery within 180 s and excellent cycling stability. The transient photovoltage technique (TPV) test confirms a non-radiative energy transfer pathway between CDs and HC-C₃N₅, excluding the possibility of electron transfer. Building on the distinct photo response characteristics of bulk C₃N₅ (B-C₃N₅), HC-C₃N₅, and CDs/HC-C₃N₅, this study further explores their potential in multi-layered anti-counterfeiting labels and a time-resolved encryption system, enabling dynamic optical information encoding. This work not only reveals the key role of the FRET mechanism over CDs in modified photochromic materials, but also paves the way for next-generation anti-counterfeiting and secure data storage applications.

Synthetic RNA nanostructures are typically composed of four nucleotides (A, U, G, and C) following a canonical base pairing rule (A-U/G-C). G·U wobble pairs are commonly employed in many RNA nanostructures, but other non-canonical base pairing remains underexplored. In this work, we design RNA nanostructures with only three nucleotides instead of four. Besides Watson-Crick G-C base pairs, we incorporate A·C non-canonical base pairs into this three-letter coding scheme and allow selective nanostructure assembly from mixed DNA templates. With the new paradigm, we produce a variety of RNA nanostructures, further expanding the possibilities of rational molecular design.

As deep neural networks (DNNs) continue to advance computer vision, natural language processing, and medical diagnostics, their reliance on 32-bit full-precision weights imposes substantial model size and computational burdens that hinder deployment at the edge; to improve efficiency, we adopt ternary neural networks (TNNs). Here, we present a ternary circuit composed of two parallel indium-gallium-zinc-oxide (IGZO) thin-film phototransistors (TFPTs) and a resistor, exhibiting three stable, discrete current states 'OFF', 'Intermediate', and 'ON' that map to the ternary weight set {-1, 0, 1}; we further realize a compact ternary inverter using only two IGZO TFPTs and two resistors, avoiding complex binary CMOS logic. The processing path begins with optical sensing, wherein the incident light power densities and wavelength determine discrete voltage outputs; during preprocessing, these voltages discretize pixel values (0-255) into multiple intervals that are supplied to the TNN for image recognition. Leveraging this integrated sensing, preprocessing and inference hardware module, we achieve >90% accuracy on CIFAR-10, thereby validating device-level data discretization and transformation and charting a path toward integrated neuromorphic vision systems.

DNA nanostructures offer programmable architectures with precise ligand arrangement, yet their in vivo utility is often limited by structural fragility and rapid systemic clearance. Here, we present a robust platform for the sustained delivery of structurally dense, multi-helical square block DNA nanostructures (SQBs) by encapsulating them within a biodegradable hydrogel composed of thiolated hyaluronic acid (HA) and gelatin. Distinct from DNA-based hydrogels where the DNA network serves as the structural matrix, this platform employs a decoupled architecture that entraps SQBs as discrete nanoparticles within a tunable polymeric matrix. This platform is engineered to maintain an Mg²⁺-rich microenvironment to preserve the structural integrity of SQB cargo, as evidenced by the intact morphology of nanostructures recovered from the matrix, while allowing independent control over degradation and release kinetics. In vitro, encapsulated SQBs retained their electrophoretic stability and exhibited release profiles governed by the hydrogel's crosslinking density and gelatin content. Importantly, SQB-hydrogel hybrids demonstrated sustained intracellular uptake in RAW 264.7 macrophages for up to 5 days, whereas free SQBs were rapidly internalized and cleared within 3 days. In vivo subcutaneous administration further confirmed that the hybrid system maintained detectable fluorescence for 10 days, significantly outperforming free SQBs, which were cleared within 24 hours. These findings establish a versatile hydrogel framework that effectively serves as a sustained depot for complex DNA nanostructures, offering a generalizable strategy for their localized and long-term deployment in therapeutic applications.

Constructing a heterointerface has become a preferred strategy for the hydrogen evolution reaction (HER) due to the synergistical H₂O dissociation and *H adsorption. Ni/Ni(OH)₂ hybrid catalysts with an isogenous heterointerface have exhibited great potential in the alkaline HER. However, designing high performance Ni/Ni(OH)₂ and understanding the catalytic mechanisms still remains challenging. Herein, we demonstrate that the HER performance of Ni/Ni(OH)₂ depends significantly on the interface density and deprotonation. Experimentally, Ni and Ni(OH)₂ grains are refined to enlarge the interface density at elevated temperature, and the activity and stability are rationally tuned by delicately regulating deprotonation at various oxidization potentials. Theoretical calculations reveal that the deprotonation energy decreases with grain refinement, which promotes the interface electron redistribution. The deprotonation lowers the H₂O dissociation energy and alleviates *H adsorption, but the excessive deprotonation leads to strong *OH adsorption, retarding H₂O dissociation, whereas the stability is enhanced. The optimum Ni/Ni(OH)₂ hybrid catalyst reaches an outstanding HER performance with an overpotential of 30 mV@10 mA cm^-2 and stable activity for over 300 hours at an extremely large current density (2.0 A cm^-2), surpassing most of the reported HER catalysts. This work initiates a new pathway to improving catalytic performance by regulating the interface density and valence state.

MXene, a two-dimensional (2D) material known for its high electrical conductivity, abundant surface functional groups, various types, and tunable morphology, has emerged as a promising material for widespread applications. Liquid metal (LM), characterized by its fluidic nature, excellent thermal/electrical conductivity, and self-healing properties, has also attracted significant interest from the scientific community. Recently, the integration of MXene with LM has gained great attention in rechargeable batteries due to its ability to overcome challenges such as volume expansion of electrode materials, dendrite formation, and interface instability. The synergistic combination of MXene and LM has shown some special properties in promoting the electrochemical performance of batteries, particularly in lithium-ion, lithium-metal, and zinc-ion batteries. These MXene/LM composites can serve as high-performance anodes, versatile interface layers, or flexible current collectors, contributing to improved battery efficiency, stability, safety, and cycling life. This review offers an in-depth analysis of the latest developments in MXene/LM composites for the first time, highlighting their applications in the field of next-generation high-energy-density rechargeable batteries. Furthermore, this review explores the future prospects and potential avenues for research in this rapidly evolving domain.

Photocatalytic hydrogen evolution on bithiazole (Tz)-based conjugated polymers was demonstrated for the first time, establishing Tz as a new building block beyond conventional benzothiadiazole (BT) systems. Two Tz-based donor-acceptor polymers were synthesized: one consisting of fluorene and Tz units (PFOTz), and the other incorporating a thiophene π-spacer between Tz units (PFOTzT). The use of thiophene-incorporating PFOTzT leads to a more ordered nanostructure within the resulting nanoparticles, promoting stronger interchain interactions and red-shifted absorption. Photocatalytic nanoparticles were prepared via mini-emulsion and nanoprecipitation methods with various surfactants. The hydrogen evolution reaction (HER) performance was evaluated under visible-light irradiation using ascorbic acid as the sacrificial electron donor. Both Tz-based polymers showed HER activity, but PFOTzT exhibited significantly higher HER activity. Time-resolved photoluminescence and transient absorption spectroscopy revealed that its superior performance arises from efficient exciton dissociation and suppressed charge recombination, resulting in prolonged carrier lifetimes. These results establish Tz as an alternative to BT in the design of high-performance organic photocatalysts and underscore the crucial impact of nanoscale morphology and interfacial engineering on photocatalytic efficiency.

Lithium-sulfur batteries (LSBs) hold significant promise for next-generation energy storage due to the ultrahigh potential energy density. However, their commercialization is hindered by the shuttle effect and sluggish reaction kinetics of lithium polysulfides (LiPSs). Herein, a hierarchical catalyst composed of cubic Mo₂C nanoparticles anchored on N-doped carbon nanospheres (δ-B-Mo₂C@NC) is designed via facile boron-doping engineering, which simultaneously mitigates LiPS shuttling and facilitates sulfur conversion reactions. The incorporation of boron dopants into the δ-B-Mo₂C@NC framework significantly increases active sites and enhances electron/ion pathways, synergistically promoting strong adsorption and efficient catalytic conversion for LiPSs. Moreover, the electronic structure of δ-B-Mo₂C is optimized by upshifting the Mo d-band center. This enhancement promotes stronger Mo 4d/S 3p orbital hybridization between δ-B-Mo₂C@NC and LiPSs, thus accelerating sulfur redox kinetics. Consequently, the LSB equipped with the δ-B-Mo₂C@NC catalyst exhibits remarkable rate capability (459 mAh g^-1 at 3 A g^-1) and long-term cycling stability (a capacity decay of 0.045% per cycle over 500 cycles at 1 A g^-1). These findings highlight the potential of Mo₂C-based catalysts in suppressing the shuttle effect and pave the way for designing advanced electrocatalysts toward high-energy and long-life LSBs.

Ferroptosis, characterized by iron-dependent lipid peroxidation, represents a promising therapeutic target for cancer treatment. Strategies that disrupt intracellular antioxidant systems to induce ferroptosis in cancer cells have been extensively explored. Herein, we developed a pH-responsive phototheranostic agent (designated as FSB₄Ca NPs) by encapsulating conjugated boron dipyrromethene tetramers (B4) within ferric ion-sulfasalazine metallo-network polymer-coated calcium carbonate hollow nanoparticles. Sulfasalazine, a known ferroptosis inducer that inhibits System X_c^--mediated cysteine influx, synergizes with ferric ion-driven glutathione (GSH) depletion to collectively amplify intracellular lipid peroxidation. In addition to serving as a second near-infrared (NIR-II) fluorophore for tracking the in vivo distribution of FSB₄Ca NPs, B4 mediates a photothermal effect that significantly enhances lipid peroxidation induction by boosting the Fenton catalytic activity of ferrous ions. Combined with localized 915-nm laser irradiation, intravenously administered FSB₄Ca NPs achieved substantial tumor suppression in mouse models, with a complete remission rate of 80%. This study establishes a facile strategy for developing long-circulating NIR-II phototheranostic agents with self-amplified lipid peroxidation induction capacity, enabling photothermally augmented ferroptosis for cancer therapy.

CAR-T cell therapy has led to remarkable advances in the outcomes of patients with acute lymphoblastic leukemia (ALL), B cell lymphomas, and multiple myeloma. Given these successes in hematologic malignancies, extensive efforts are now focused on developing CAR-T cell therapies to treat solid tumors. The treatment of solid tumors poses significant hurdles with cell trafficking necessary to achieve efficacy and minimize off-tumor side effects. The development of simple, safe and inexpensive modalities for tracking CAR-T cell distribution in clinical use in vivo could provide critical insights to facilitate the development of improved CAR-T products for solid tumors. Here, we demonstrate a strategy to monitor CAR-T cells in vivo using ultrasound imaging of nanobubble (NB) labeled cells. NBs are ultrasound contrast agents composed of a lipid shell and a C₄F₁₀ gas core that can be efficiently internalized into cells. This approach enables us to image the CAR-T cells using nonlinear contrast-enhanced ultrasound (CEUS). Utilizing this method, we found that CAR-T cells can be visualized after injection into both tumor-bearing and non-tumor bearing mice. In summary, our ultrasound-based tracking approach can effectively monitor the trafficking of CAR-T cells in vivo, offering a valuable new strategy that can further enable the development of new CAR-T products and strategies to modulate cell trafficking.