Room-temperature phosphorescent materials for tumor imaging: from structural design to diagnosis

Abstract

Compared to fluorophores, room-temperature phosphorescent (RTP) materials exhibit advantages in time-resolved imaging due to their relatively long luminescence lifetime. RTP materials circumvent interference from autofluorescence in biological tissues effectively, thereby enabling low-cost and high-resolution tumor imaging. This review summarized the mechanisms of phosphorescent radiative transitions, including key factors such as molecular orbital arrangements, spin–orbit coupling, and intermolecular interactions. The impact of chemical structures on phosphorescence quantum yield and photostability of RTP materials was emphazized. Furthermore, we reviewed recent advances in organic molecules, metal complexes and nanomaterials for tumor imaging, with a focus on the structural optimization and tumor microenvironment-responsive design. Light and X-ray as activation sources were compared for RTP materials. Finally, we proposed strategies to overcome clinical translation challenges, aiming to guide the design of RTP materials suitable for precise tumor diagnosis.