Low-dose X-ray-stimulated LaGaO₃:Sb,Cr near-infrared persistent luminescence nanoparticles for deep-tissue and renewable in vivo bioimaging

X-ray-stimulated near-infrared persistent luminescence nanoparticles (NIR-PLNPs) offer attractive capabilities for autofluorescence free deep-seated imaging and depth-independent treatment, but still suffer from adverse effects caused by high-dose X-ray irradiation (>5 Gy). From the viewpoint of two centers of NIR-PLNPs, i.e., X-ray photon absorption center and defects center, we here propose a top-down composition design strategy for the development of low dose X-ray-stimulated NIR-PLNPs with improved X-ray photon absorption efficiency and optimized persistent luminescence (PersL) performance. Successfully, hypersensitive X-ray-stimulated NIR-PLNPs LaGaO₃:Sb³⁺,Cr³⁺ with a super-long PersL emission (>500 h) at ∼750 nm are prepared. The nature of high Z atomic constituents of the host LaGaO₃ endows these NIR-PLNPs with strong X-ray absorption capacity. Simply by codoping with size-mismatched ions Sb³⁺, the concentration of oxygen vacancies in the host is rationally optimized, leading to the enhanced NIR PersL performance of Cr³⁺ ions. In vivo bioimaging demonstrates that the designed X-ray-stimulated NIR-PLNPs LaGaO₃:Sb³⁺,Cr³⁺ can be readily reactivated under X-ray irradiation with even a lower dose to 0.37 Gy, showing the advantages of these nanoparticles on deep-seated imaging and treatment. More importantly, we anticipate that our proposed top-down composition design strategy can be applied to develop much low dose X-ray-stimulated NIR-PLNPs in the future.