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ConspectusX-ray luminescence is an optical phenomenon in which chemical compounds known as scintillators can emit short-wavelength light upon the excitation of X-ray photons. Since X-rays exhibit well-recognized advantages of deep penetration toward tissues and a minimal autofluorescence background in biological samples, X-ray luminescence has been increasingly becoming a promising optical tool for tackling the challenges in the fields of imaging, biosensing, and theragnostics. In recent years, the emergence of nanocrystal scintillators have further expanded the application scenarios of X-ray luminescence, such as high-resolution X-ray imaging, autofluorescence-free detection of biomarkers, and noninvasive phototherapy in deep tissues. Meanwhile, X-ray luminescence holds great promise in breaking the depth dependency of deep-seated lesion treatment and achieving synergistic radiotherapy with phototherapy.In this Account, we provide an overview of recent advances in developing advanced X-ray luminescence for applications in imaging, biosensing, theragnostics, and optogenetics neuromodulation. We first introduce solution-processed lead halide all-inorganic perovskite nanocrystal scintillators that are able to convert X-ray photons to multicolor X-ray luminescence. We have developed a perovskite nanoscintillator-based X-ray detector for high-resolution X-ray imaging of the internal structure of electronic circuits and biological samples. We further advanced the development of flexible X-ray luminescence imaging using solution-processable lanthanide-doped nanoscintillators featuring long-lived X-ray luminescence to image three-dimensional irregularly shaped objects. We also outline the general principles of high-contrast

Cell temperature monitoring is of great importance to uncover temperature-dependent intracellular events and regulate cellular functions. However, it remains a great challenge to precisely probe the localized temperature status in living cells. Herein, we report a strategy for in situ temperature mapping on an immune cell membrane for the first time, which was achieved by using the lanthanide-doped upconversion nanoparticles. The nanothermometer was designed to label the cell membrane by combining metabolic labeling and click chemistry and can leverage ratiometric upconversion luminescence signals to in situ sensitively monitor temperature variation (1.4% K

Solution-processed scintillators hold great promise in fabrication of low-cost X-ray detectors. However, state of the art of these scintillators is still challenging in their environmental toxicity and instability. In this study, we develop a class of tetradecagonal CuI microcrystals as highly stable, eco-friendly, and low-cost scintillators that exhibit intense radioluminescence under X-ray irradiation. The red broadband emission is attributed to the recombination of self-trapped excitons in CuI microcrystals. We demonstrate the incorporation of such CuI microscintillator into a flexible polymer to fabricate an X-ray detector for high-resolution imaging with a spatial resolution up to 20 line pairs per millimeter (lp mm−1), which enables sharp image effects by attaching the flexible imaging detectors onto curved object surfaces.

： Colloidal nanocrystal scintillators hold great potential in fabricating large-area, flexible X-ray detectors for high-resolution X-ray imaging of highly curved, irregularly shaped objects. The synthesis of high-efficiency, high-stability nanoscintillators is of great importance for the development of X-ray imaging detectors. In this study, we develop a class of cerium (Ce3+)-sensitized core-shell nanoscintillators that are suitable for achieving flexible X-ray luminescence imaging. We demonstrate that an epitaxial growth of NaGdF4:Ce(60%) on the surface of NaGdF4:Eu(15%) nanoscintillators as a sensitization layer allows for enhancing X-ray-induced radioluminescence. We reveal that the enhancement of X-ray luminescence in nanoscintillators could be attributed to the synergistic effect of high-Z composition-induced X-ray absorption, Ce3+ sensitization, and surface passivation to relieve energy quenching. By incorporating the nanoscintillators into a flexible elastomer of polydimethylsiloxane (PDMS), we demonstrate its utility in high-resolution flexible X-ray luminescence imaging.

Clinically approved photodynamic therapy (PDT) has emerged as an alternative treatment for cancers and malignant diseases; however, high quality PDT agents were still in great demand. Herein, the van der Waals (vdW) heterostructure of graphitic carbon nitride (g-C3N4, abbreviated as CN here) and metallic molybdenum disulfide (1T-MoS2, abbreviated as MS here) was fabricated, PEGylated, and then investigated. By making use of the extraordinary antenna effect and the ultrafast electron transfer rate of metallic molybdenum disulfide, as well as the efficient separation of photogenerated electron-hole pairs of the final heterojunction, massive reactive oxygen species (ROS) can be generated under 670 nm laser irradiation together with the as-synthesized g-C3N4@1T-MoS2 vdW nanostructure (CNMS), which should be largely owed to the appealing photocatalytic water splitting property of the CNMS structure. It was well proved by the in vitro studies that the intracellularly produced ROS can result in cell death, by the way of inducing cell apoptosis and/or necrosis through mediating phosphatidylserine ectropion, mitochondrial depolarization, and chromosomal DNA fragmentation, as well as up-regulating the expression of apoptosis-related proteins and unbalancing intracellular redox homeostasis. In vivo exploration also gave out satisfactory results that the tumor growth could be significantly inhibited by the photodynamic therapy. Additionally, outstanding biocompatibility and biosafety were also guaranteed. All these results provided compelling evidences for that the CNMS vdW heterostructure is an aussichtsreich nano-photosensitizer, and may provide some fresh ideas for the developing of nanomedicine for PDT application.