White-Light-Excited Organic Room-Temperature Phosphorescence for Improved In Vivo Bioimaging

Abstract Organic phosphorescence materials offer significant advantages for bioimaging applications. However, most of these materials are excited exclusively by ultraviolet (UV) light, which poses risks to living organisms. Herein, six donor-acceptor type compounds incorporating triazine groups were designed as guests within a doped system. The triazine groups exhibit strong absorption capabilities, enabling the guests to achieve white-light-excited phosphorescence, ultimately resulting in the doped materials displaying a bright afterglow lasting 3-5 s under white-light excitation. The phosphorescence quantum yields of the doped system range from 15% to 75%, with lifetimes between 176 and 401 ms. By leveraging the ability of white-light to penetrate biological tissues, a bioimaging mode which the materials are first concentrated within the organism and then excited was developed, yielding superior imaging effects compared to the traditional method where materials are first excited and then concentrated. Furthermore, these materials were applied in the imaging diagnosis of arteriosclerosis plaques and intestinal diseases, as well as in the navigation for in situ liver tumor surgery, achieving excellent imaging outcomes. This work addresses the limitation of phosphorescent materials relying on UV-light, significantly enhancing their potential for practical applications in clinical imaging.