Transparent Ce3+-doped nano-glass composites (nano-GCs) embedded with pure and Gd3+-mixed KLaF4 nanocrystals (NCs) are prepared by a cost-effective and reproducible glass-making and thermal treatment method. The nano-GCs can be readily cast into various sizes and shapes. The growth of the Gd3+-mixed NCs and the enrichment of Ce3+ in the NCs are unambiguously revealed. Significantly enhanced emissions of Ce3+ with a photoluminescence quantum yield as high as 92.7% are observed in the nano-GCs embedded with the Gd3+-mixed NCs. The integral X-ray excited emission intensity of the nano-GC is 170% that of the Bi4Ge3O12 (BGO) single crystal. A light output of about 853 ± 8 ph per MeV with an energy resolution of 22.27% is obtained using the nano-GC for γ-ray (662 keV) detection. The Monte Carlo simulation is carried out to understand the differences in X- and γ-ray responses. As a proof-of-concept, a real-time remote X-ray fiber dosimeter is constructed using a scintillating fiber made out of the nano-GC, which shows an excellent linear response with the irradiation dose, good thermal stability and radiation hardness.
Yong’an Tang,Jun Hu,Ahmed H. Elmenoufy,Xiangliang Yang
Photodynamic therapy (PDT) for deep-seated tumor is largely impeded by the limited penetration depth of excitation light in tissue. X-ray is considered as an ideal energy source to activate photosensitizers (PSs) located deep within the body with the assistance of scintillating nanoparticles (ScNPs). However, the efficacy under this concept is not satisfying due to the low scintillating luminescence and weak energy transfer from ScNPs to PSs. Here, mesoporous LaF3:Tb ScNPs were successfully synthesized by a facile hydrothermal process to act as PS carriers and X-ray energy transducers, owing to their good ionizing radiation stopping power and high luminescence efficiency. The formation mechanism of porous structure was elucidated in detail with classical crystallization theory. After a systematic investigation, LaF3:Tb ScNPs with optimized scintillating luminescence were obtained for loading Rose Bengal (RB) to establish an efficient FRET system, owing to their excellent spectral match. The FRET efficiency between ScNPs and RB was calculated to be as high as 85%. Under irradiation, enhanced 1O2 generation induced by LaF3:Tb-RB nanocomposites via FRET process was detected. This LaF3:Tb-RB FRET system shows great potential to be applied in X-ray stimulated PDT for deep-seated tumors in the future.
危险品化学品经营许可证（带存储）