Room-Temperature Phosphorescent Materials for Tumour 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 effectively circumvents interference from autofluorescence in biological tissues, thereby enabling low-cost and high-resolution tumour imaging. This review summarised the mechanisms of phosphorescent radiative transitions, including key factors such as molecular orbital arrangements, spinorbit coupling, and intermolecular interactions. The impact of chemical structures on phosphorescence quantum yield and photostability of RTP materials was emphasised. Furthermore, we reviewed recent advances in organic molecules, metal complexes and nanomaterials for tumour imaging, with a focus on the structural optimisation and tumour 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 tumour diagnosis.