"All-in-One" Photochemical Afterglow Nanoplatform Based on Perovskite Quantum Dots

Photochemical reaction-based afterglow materials offer a promising solution to the tissue autofluorescence issues associated with real-time excitation in traditional fluorescence probes. Conventional photochemical afterglow systems typically consist of three components: a photosensitizer, an energy cache unit (ECU), and an emitter. However, their physical separation leads to inefficient energy transfer. We present a strategy for constructing an "all-in-one" afterglow nanoplatform (AGNP) based on perovskite quantum dots (PQDs) to enhance the energy transfer efficiency by minimizing physical separation. Modified with 1-pyrenecarboxylic acid (PCA), CsPbBr₃ PQDs can serve as a photosensitizer, emitter, and ECU-phenylacetic acid (ECU-COOH) host simultaneously. The afterglow intensity of the AGNP shows a remarkable 30-fold enhancement compared with the separated ECU afterglow system, attributed to the decreased energy transfer distance. The AGNP also exhibits great versatility, enabling tunable afterglow emission across the visible region. The AGNP is further adopted for in vivo afterglow imaging with a signal-to-noise ratio of 41. This work provides an idea for constructing "all-in-one" afterglow systems and demonstrates their potential for background-free bioimaging.