Xiuping Gao

长余辉纳米发光材料的发光性能与缺陷结构密切相关，但不同纳米化策略对缺陷类型及陷阱结构的调控机制尚不明确。本文以Zn₂SiO₄:Mn²⁺,Yb³⁺,Li⁺长余辉体系为研究对象，分别采用自上而下（TD）和自下而上（BU）两种策略制备纳米颗粒，系统研究其晶体结构、缺陷结构、陷阱行为及光动力治疗（PDT）性能之间的关联。结果表明，TD球磨纳米化虽实现了颗粒细化，但引入大量表面无序和晶界缺陷，导致有效浅陷阱持续减少，发光强度和余辉性能显著下降；BU模板法则获得粒径约150 nm、分散均一的纳米颗粒，并形成丰富的自由体积缺陷与开放界面结构。热释光分析表明，约0.74 eV浅陷阱是维持室温长余辉的关键储能中心；正电子湮没寿命谱进一步证实，BU样品中自由体积缺陷显著增加，有利于载流子迁移及界面能量传递。PDT实验表明，BU样品对HeLa细胞的死亡率优于TD样品，表现出最佳光动力治疗效果。研究表明，长余辉PDT性能主要受缺陷类型、陷阱结构和界面能量传递协同调控，而非单纯依赖发光强度。本工作为长余辉纳米材料的缺陷工程设计及生物医学应用提供了新的物理机制依据。

Persistent luminescence nanoparticle scintillators (PLNS) have been attempted for X-ray-induced photodynamic therapy (X-PDT) because persistent luminescence after ceasing radiation can make PLNS use less cumulative irradiation time and dose to generate the same amount of reactive oxygen species (ROS) compared with conventional scintillators to combat cancer cells. However, excessive surface defects in PLNS reduce the luminescence efficiency and quench the persistent luminescence, which is fatal to the efficacy of X-PDT. Herein, the PLNS of SiO₂@Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺ was designed by the energy trap engineering and synthesized by a simple template method, which has excellent X-ray and UV-excited persistent luminescence and continuously tunable emission spectra from 520 to 550 nm. Its luminescence intensity and afterglow time are more than 7 times that of the reported Zn₂SiO₄:Mn²⁺ used for X-PDT. By loading a Rose Bengal (RB) photosensitizer, an effective persistent energy transfer from the PLNS to photosensitizer is observed even after the removal of X-ray irradiation. The X-ray dose of nanoplatform SiO₂@Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺@RB in X-PDT of HeLa cancer cells was reduced to 0.18 Gy compared to the X-ray dose of 1.0 Gy for Zn₂SiO₄:Mn for X-PDT. This indicates that the Zn₂SiO₄:Mn²⁺, Yb³⁺, Li⁺ PLNS have great potential for X-PDT applications.

The multifunctional nanoplatform combining persistent luminescent nanoparticles (PLNPs) and metal–organic frameworks (MOFs) can be used for in vivo imaging and tumor therapy, providing a new strategy for effective tumor diagnosis and treatment.

A novel near-infrared persistent luminescent phosphor Na₂CaSn₂Ge₃O₁₂(NCSGO) doped with Ho³⁺, Er³⁺, Tm³⁺and Yb³⁺was synthesized by a high-temperature solid-state reaction.