Reversible Fluorescent Detection of Redox Dynamics in Living Systems.

Redox homeostasis is essential for cellular function and organismal health, and its dysregulation is linked to inflammation, cancer, and neurodegenerative diseases. Precise, dynamic monitoring is critical yet challenging due to the reversible and fluctuating nature of redox processes. Fluorescent probes offer a promising solution through non-invasiveness, high sensitivity, and reversible responsiveness. This Perspective systematically reviews recent advances in reversible fluorescent probes for tracking redox homeostasis, focusing on four major sensing mechanisms: FRET, ICT, PET, and ESPT. For each, we evaluate applicability, reversibility, response kinetics, and signal stability across diverse redox contexts. We further highlight that integrating reversible probes with high-throughput or multiplexed imaging platforms will be essential to advance redox monitoring from static snapshots to dynamic network-level analysis.