Optothermal-Stimulated Persistent Luminescence Imaging and Therapy (OSPLIT)

Persistent luminescent nanomaterials have significantly advanced in vivo bioimaging and biosensing by emitting photons after excitation ceases, effectively minimizing tissue autofluorescence. However, their application in biomedical fields such as tumor theranostics is limited by low brightness and rapid signal decay. To address these issues, OSPLIT (optothermal-stimulated persistent luminescence imaging therapy), a dual-function strategy for imaging and treatment is introduced. The OSPLIT approach enhances the release of charge carriers from deep traps in lanthanide-doped nanoparticles, resulting in a 73 fold increase in persistent luminescence within the second near-infrared (NIR-II) window. In living mice, it enables high-contrast imaging of lymph node metastases, with a signal-to-background ratio 11.8 times greater than conventional NIR-II fluorescence. Optothermal-boosted nanoparticles are effective in ablating lymph node metastasis and preventing tumor spread. These findings highlight the potential of optothermal stimulation to enhance persistent luminescence for both imaging and therapeutic applications.