Oxygen vacancy engineering in LaInO3:Nb,Cr for X-ray-excited near-infrared persistent bioimaging

Bioimaging is essential in medical diagnostics and research, yet conventional optical methods are limited by photobleaching and background interference. Although near-infrared (NIR) persistent luminescent (PersL) materials avoid in situ excitation and autofluorescence, their signal decay and shorter-wavelength emission restrict long-term repetitive imaging. Here, we report an oxygen-vacancy-tailoring strategy in LaInO 3 :Nb,Cr, which exhibits broad NIR emission centered at 845 nm, efficient X-ray charging, and repeatable red-light recharging. Benefiting from its high-atomic-number host, LaInO 3 exhibits strong X-ray absorption, while Nb 5+ doping modulates oxygen vacancy (V O ), thereby boosting Cr 3+ NIR PersL by approximately 13 times. In vivo imaging reveals that LaInO 3 :Nb,Cr nanoparticles can be reactivated with a low X-ray dose (0.20 Gy) and repeatedly recharged in situ by red light, highlighting their potential for deep-tissue imaging. This work provides insights into defect-property relationships via ion doping and offers guidance for the rational design of PersL materials for practical applications.