Recent development of fluorescent probes for hydrogen per/polysulfides

While there is a burgeoning understanding of the overall importance of hydrogen per/polysulfides (H₂S_n, n ≥ 2) in human health, their specific biological roles and mechanisms of action remain unclear. To better understand these critical details, fluorescent probes have been developed to monitor these sulfur species in real-time. The identification of H₂S_n-specific recognition moieties and compatible fluorescent dyes has become increasingly critical to the development of sensitive and selective fluorescent probes for H₂S_n. Probes reported between 2023 and 2026 encompass a broad range of chemical strategies to achieve selectivity in detection and to optimize fluorescence turn-on, with a large focus on leveraging the greater nucleophilicity of H₂S_n over hydrogen sulfide and other biothiols. In this short review, we summarize the most recent strategies for H₂S_n fluorescent probe design and discuss key considerations for their future development and applications in biological systems.