X‐ray imaging holds great promise in medical diagnosis, industrial nondestructive examination, and security screening. However, developing scintillators that simultaneously achieve high spatial resolution and long‐term operational stability remains a significant challenge. Herein, Tb 3+ ‐ and Eu 3+ ‐doped small‐sized CsLu 2 F 7 (CLF) nanocrystal scintillators are reported. The high atomic numbers of Cs and Lu enhance X‐ray attenuation, while nanocrystal dimensions minimize light scattering, enabling the fabrication of transparent, thin scintillator films with efficient X‐ray interaction. The nanocrystals exhibit green (Tb 3 ⁺) or red (Eu 3 ⁺) emission, and demonstrate a low detectable dose rate of 0.48 µGy s −1 for Tb 3 ⁺ doped CLF. Importantly, the nanocrystal scintillators possess excellent long‐term stability against high‐dose X‐ray irradiation, humidity, and elevated temperature. Incorporation of nanocrystals into waterborne polyurethane (PU), CLF‐25%Tb@PU films, yields a high spatial resolution of 30 lp mm −1 and a film thickness of ≈ 200 µm. Notably, these films enable high‐contrast 2D projection imaging of various objects. These results highlight the great potential of as‐prepared scintillators in X‐ray imaging applications.

Near-infrared ratiometric imaging holds significant promise for real-time in vivo detection and spatial mapping of inflammation across physiological and pathological contexts. However, conventional nanoprobes are constrained by emission wavelengths below 1600 nm, limiting tissue penetration from scattering and absorption of endogenous chromophores. To address this, a ratiometric nanoprobe based on Tm3+-doped nanoparticle is engineered with emission at 1811 nm, to leverage deep-tissue penetration and enhance signal-to-noise ratio under dual-wavelength excitation, 808 nm and 980 nm. Conjugation with IR-806, which is responsive to selective recognition of hypochlorite (ClO-), enables the nanoprobe to give out analyte-dependent emission under 808 nm excitation, while a stable, analyte-independent reference signal under 980 nm irradiation. These two-excitation-mode and responsive emission benefit self-calibration to mitigate non-specific interferences. A detection limit of 300 nM is achieved for inflammatory marker, ClO-, surpassing the sensitivity required for inflammatory diagnosis. Benefiting from the dual long-wavelength excitation and emission modalities, precise dynamic ratiometric imaging of ClO- is achieved in deep tissues. The nanoprobe successfully maps the inflammation sites and monitors ClO- fluctuations in arthritis and intestinal inflammation. These findings advance the design of second near-infrared (NIR-II) ratiometric nanoprobes and hold promise for in vivo diagnostics of inflammation in anatomically deep or optically dense tissues.

The exploration of support effect and interface effect on a homogeneous-heterogeneous hybrid CO2 reduction photocatalytic system is deficient. Herein, we constructed oxides (WO3, Al2O3, SiO2, TiO2, and CuO) supported Co-based photocatalysts via an incipient wetness impregnation method for visible-light driven CO2 reduction with the assistance of a photosensitizer ([Ru(bpy)(3)]Cl-2) and a sacrificial electron donor (triethanolamine) under mild conditions. Among them, the WO3 supported Co-based photocatalyst (named 1Co/W) exhibited the highest CO generation rate (29.34 mu mol h(-1)) with 81% selectivity and 0.73% apparent quantum yield. Moreover, the unit mass activity of surface Co components was up to 296.35 mmol g(Co)(-1) h(-1). Experimental studies and characterization analyses indicated that the superior photocatalytic performance of 1Co/W benefited from the following aspects: (1) the well-matched band structure between 1Co/W and the photosensitizer for charge transfer and the suitable conduction band position for CO2 conversion; (2) the tight interface structure between surface Co active species and WO3 support accelerating the carrier migration kinetics and providing efficient cobalt active sites for CO2 adsorption and activation; and (3) the dispersion and stabilization effect of WO3 on surface Co active species.

Metal fluoride nanocrystals are widely used in biomedical studies owing to their unique physicochemical properties. The release of metal ions and fluorides from nanocrystals is intrinsic due to the solubility equilibrium. It used to be considered as a drawback because it is related to the decomposition and defunction of metal fluoride nanocrystals. Many strategies have been developed to stabilize the nanocrystals, and the equilibrium concentrations of fluoride are often <1 mM. Here we make good use of this minimum amount of fluoride and unveil that metal fluoride nanocrystals could effectively induce desilylation cleavage chemistry, enabling controlled release of fluorophores and drug molecules in test tubes, living cells, and tumor-bearing mice. Biocompatible PEG (polyethylene glycol)-coated CaF2 nanocrystals have been prepared to assay the efficiency of desilylation-induced controlled release of functional molecules. We apply the strategy to a prodrug activation of monomethyl auristatin E (MMAE), showing a remarkable anticancer effect, while side effects are almost negligible. In conclusion, this desilylation-induced cleavage chemistry avails the drawback on empowering metal fluoride nanocrystals with a new function of perturbing or activating for further biological applications.

Influenza A virus (IAV) poses a significant threat to human health, which calls for the development of efficient detection methods. The present study constructed a fluorescence resonance energy transfer (FRET) system based on novel fluorescent probes and graphene oxide (GO) for detecting H5N1 IAV hemagglutinin (HA). Here, we synthesized small (sub-20 nm) sandwich-structured upconversion nanoparticles (UCNPs) (SWUCNPs for short) with a high energy transfer efficiency, which allows for controlling the emitter in a thin shell. The π–π stacking interaction between the aptamer and GO shortens the distance between the fluorescent probe and the receptor, thereby realizing fluorescence resonance energy transfer (FRET). When HA is present, the aptamer enables changes in their conformations and move away from GO surface. Fluorescence signals display a linear relationship between HA quantitation in the range of 0.1–15 ng mL–1 and a limit of detection (LOD) of 60.9 pg mL–1. The aptasensor was also applicable in human serum samples with a linear range from 0.2 to 12 ng mL–1 and a limit of detection of 114.7 pg mL–1. This strategy suggested the promising prospect of the aptasensor in clinical applications because of the excellent sensing performance and sensitivity. This strategy may be promising for vitro diagnostics and provides new insights into the functioning of the SWUCNPs system.

Compared with photon-induced binary cancer therapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), boron neutron capture therapy (BNCT) emerges as an alternative noninvasive treatment strategy that could overcome the shallow penetration of light. One key factor in performing successful BNCT is to accumulate a sufficient amount of B-10 (>20 ppm) within tumor cells, which has been a long-standing challenge for small-molecule-based boron drugs. Boron nitride nanoparticles (BNNPs) are promising boron carriers due to their high boron content and good biocompatibility, as certain types of BNNPs can undergo rapid degradation under physiological conditions. To design an on-demand degradable boron carrier, BNNPs were coated by a phase-transitioned lysozyme (PTL) that protects BNNPs from hydrolysis during blood circulation and can be readily removed by vitamin C after neutron capture therapy. According to PET imaging, the coated BNNPs exhibited high tumor boron accumulation while maintaining a good tumor to nontumor ratio. Tail-vein injections of vitamin C were followed by neutron irradiation, and BNNPs were found to be rapidly cleared from major organs according to ex vivo ICP-OES analysis. Compared with the control group, animals treated with BNCT showed suppression of tumor growth, while almost negligible side effect was observed. This strategy not only utilized the high boron content of BNNPs but also successfully performed an on-demand degradation of BNNPs to avoid the potential toxicity caused by the long-term accumulation of nanoparticles.