In Vivo Ultrasound‐Induced Luminescence of Fluoride Nanocrystals

ABSTRACT In vivo luminescence technology is extensively used for monitoring, diagnosing, and treating various diseases. However, traditional photoluminescence (PL) techniques suffer from limited tissue penetration, restricting their in vivo luminescence performance. Consequently, we developed a novel ultrasonic luminescence mechanism that uses ultrasound's tissue‐penetrating capability to achieve deep in vivo luminescence from fluoride nanocrystals. Focused ultrasound (FUS) generates localized thermal effects, enabling charge carriers in fluoride nanocrystals to detach from their bonds and recombine with the emission center, resulting luminescence. By utilizing different rare earth dopants, we achieved multicolor ultrasound luminescence ranging from blue‐violet light to near‐infrared light (450–980 nm). The tissue penetration of fluoride nanocrystals under ultrasound induction reaches up to 7 mm. Furthermore, we demonstrated the feasibility of ultrasound‐guided tumor localization and treatment in mouse subcutaneous tumor models. This study systematically elucidates the luminescence mechanisms of ultrasound‐induced nanocrystals and broadens the potential applications of penetrating luminescence technologies in biomedicine.