Near-infrared persistent luminescence phosphors ZnGa2O4:Cr3 + as an accurately tracker to photothermal therapy in vivo for visual treatment

•The photothermal therapy is a good way to treat tumors.•The ICG@mZGC nanoparticles could lower signal-to-noise ratio when imaging.•This system can realize visual accurate PTT.•ICG@mZGC performs a good effect of photothermal therapy in vivo.

The photothermal therapy agents induced by 808 nm near infrared light laser have good potential for photothermal therapy (PTT) in vivo, with the advantages of harmless treatment, minimally invasion, high efficiency and deep tissue penetration. For the traditional photothermal therapy agents, however, it was impossible to track them in vivo because of the low signal-to-noise ratio, so we cannot conduct the extra near infrared light laser to radiate tumors sites accurately. Herein, we introduce a new complex: indocyanine green (ICG), near-infrared persistent luminescence (PL) phosphors ZnGa2O4:Cr3 + (ZGC) and mesoporous silica nanoparticles (MSNs) (ICG@mZGC nanoparticles) were assembled for long-lasting optical imaging to guide PTT. The results revealed that the novel nanoparticle, ICG@mZGC, could lower signal-to-noise ratio, enable highly sensitive optical detection during optical imaging-guided PTT and perform a good effect of photothermal therapy in vivo, and thus providing possibilities for mZGC to improve the localization precision of tumor sites in photothermal therapy in the body.