Photosensitizer

Gamma-ray burst

Autofluorescence

Photodynamic therapy

Biomedical engineering

Photochemistry

Materials science

Persistent luminescence

Afterglow

Singlet oxygen

Physics

Nanotechnology

Organic chemistry

Oxygen

Thermoluminescence

Optics

Astronomy

Paraffin wax

Luminescence

Photothermal therapy

Fluorescence

Composite material

Medicine

Chemistry

Optoelectronics

Advanced Functional Materials

Herein, persistent luminescence nanoparticles (PLNPs) and photosensitizer are integrated for cancer theranostics with high specificity and without the need of continuous illumination. Specifically, ZnGa 1.996 O 4 :Cr 0.004 (PLNPs) and IR780 (photosensitizer) are encapsulated by a temperature‐responsive “wax‐seal” composed of oleic acid and hexadecanol. The seal prevents luminescence quenching and premature initiation of photodynamic therapy (PDT), until it is melted down by heat stimulus. After photothermal activation, the near‐infrared afterglow offered by PLNPs provides imaging with high signal‐to‐background ratio because of the absence of tissue autofluorescence, as well as continuously excited photosensitizer for reactive oxygen species generation. Such theranostic nanoplatform offers multimodal imaging–guided localized cancer PDT.

“Wax‐Sealed” Theranostic Nanoplatform for Enhanced Afterglow Imaging–Guided Photothermally Triggered Photodynamic Therapy