Phosphorescent metal complexes for biomedical applications

Abstract

Benefiting from the application of state-of-the-art imaging techniques, phosphorescent species are gaining a surge of research interest. Phosphorescent metal complexes is an interesting emerging branch that is currently being intensively investigated, since they are distinctively different from fluorescent chromophores regarding the nature and lifetime scale of photoluminescence. Alongside the success of fundamentally non-emissive cisplatin-based compounds in anticancer therapeutics, the phosphorescent signals of the metal complexes raise an intriguing possibility of revealing the mechanism of action of the potent candidates from another perspective. Under the inherent difference in the photophysical processes, these metal complexes have been successfully exploited to a wide range of biomedical applications involving biosensing/cell staining, visualized chemotherapy (also known as theranostic), and phototherapy (especially photodynamic therapy), revealing promising potentials in serving as candidates for their organic counterparts. This review article overviews the most recent works on phosphorescent metal complexes for biomedical applications and concentrates on phosphorescent metals such as ruthenium and iridium.