SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4176-y
Three-photon microscopy (3PM) in the near-infrared-III (NIR-III) window (1600–1840 nm) enables high-resolution visualization of cerebral vasculature in vivo, but its imaging depth and quality are limited by the performance of fluorescent probes. Here, we report a probe optimization strategy transitioning from mirror symmetry to centrosymmetry, yielding a highly symmetric aggregation-induced emission (AIE) molecule, T4PQ. The centrosymmetric structure aligns donor-acceptor units, promoting uniform electron cloud delocalization and directional charge transfer, which enhances exciton formation and suppresses non-radiative decay, thereby increasing fluorescence quantum yield. This symmetry also boosts the three-photon absorption cross-section by enhancing electron delocalization and transition dipole moment, enabling stronger nonlinear optical responses under long-wavelength excitation. T4PQ nanoparticles (T4PQ NPs) exhibit an enhanced three-photon absorption cross-section, high fluorescence quantum yield, and excellent photostability. In murine models, T4PQ NPs achieved three-dimensional cerebrovascular imaging at a depth of 1785 μm and real-time hemodynamic observation in microvessels at 1006 μm depth, with good biocompatibility. These results validate the advantage of centrosymmetric molecular design for deep-brain imaging probes, offering a high-performance tool for neurovascular research.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3833-1
Developing plasmonic nanomaterials with compositions beyond noble metals is crucial for expanding their applications. Transition metal nitrides, such as titanium nitride (TiN), exhibit excellent plasmonic optical properties and photothermal conversion efficiency, showing promise in catalysis, photothermal therapy, and seawater desalination. However, the structure-property relationship governing their plasmonic optical properties remains unclear. Here, we constructed Au@TiN core-shell nanostructures and systematically investigated the tunability of their geometry, composition, and optical properties. By varying the Au core size and TiN shell thickness, we achieved precise control over the localized surface plasmon resonance (LSPR) from visible to near-infrared wavelengths. Single-particle scattering spectroscopy revealed distinct plasmon hybridization modes, with experimental spectra matching theoretical simulations. The Au@TiN nanostructures exhibited enhanced photothermal conversion efficiency (η = 78.5%) under 808 nm laser irradiation, significantly outperforming pure TiN nanoparticles (η = 45.2%). This work demonstrates multi-factor control over plasmonic effects in TiN, providing insights for designing TiN-based plasmonic nanomaterials for catalysis and sensing.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025011002
Cadmium (Cd) contamination in farmland soils poses a threat to food security, necessitating effective remediation strategies. This study prepared three types of phosphorus-enriched biochar (PBC) from rice straw and different phosphorus sources (fused calcium magnesium phosphate, citric acid-activated fused calcium magnesium phosphate, and monocalcium phosphate) to evaluate their potential in stabilizing Cd(II), releasing phosphorus, and enhancing plant resistance to heavy metal stress. Under Cd stress, PBC amendments significantly improved soil physicochemical properties and reduced Cd bioavailability through direct immobilization (adsorption, precipitation) and indirect mechanisms. Specifically, CBC and MBC treatments reduced DTPA-extractable Cd by 45.73% and 48.92%, respectively. The porous structure of biochar facilitated sustained phosphorus release, influencing soil solution phosphorus dynamics. In pot experiments with Brassica napus L., PBC application significantly improved agronomic traits and reduced oxidative stress markers. The C5 treatment increased leaf area by 100%, M7 increased plant height by 26.8%, and M3 reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents by 72.5% and 61.2%, respectively. These findings demonstrate that PBC effectively alleviates Cd toxicity, promotes plant growth, and enhances stress resistance, offering a feasible strategy for remediating Cd-contaminated soils while providing a sustainable phosphorus source.