Two-channel responsive luminescent chemosensors for dioxygen species: Molecular oxygen, singlet oxygen and superoxide anion

Structurally identical dioxygen species, including molecular oxygen, singlet oxygen and superoxide anion, have distinct physicochemical properties and biological reactivities owing to minor differences in their outer electron distributions. As biologically important oxidants, these dioxygen species have been extensively studied; however, their intricate and sometimes paradoxical biological roles have not been fully elucidated. A major challenge in understanding the in vivo behaviors of dioxygen species is the requirement for their accurate quantification and in situ distribution mapping with real-time specific recognition. Thus, more highly efficient detection methods for these species are required. Two-channel responsive luminescent sensing techniques have drawn interest as excellent tools for tracing the formation and dynamics of dioxygen species. These techniques have the advantages of high spatial and temporal resolution and self-calibration. Herein, we review recent developments in the field of two-channel responsive luminescent chemosensors for dioxygen species based on small molecules, macromolecules, and nanocomposites. We focus our discussion on features of various probes, including their sensing mechanisms, synthetic strategy, and biological applications. Finally, we discuss unresolved issues and present our perspective on future two-channel responsive luminescent sensors for dioxygen species. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Structurally identical dioxygen species have distinct physicochemical properties and biological reactivities due to minor differences in their outer electron distributions. Accurate quantification and real-time specific recognition are essential for understanding the in vivo behaviors of dioxygen species. Two-channel responsive luminescent sensing techniques show promise for tracing the formation and dynamics of dioxygen species with high spatial and temporal resolution.