Rational design of a rapidly responsive and highly selective fluorescent probe for SO₂ derivatives detection and imaging

Sulfur dioxide (SO2) is emerging as a double-edged molecule, while plays vital roles in food and biological system. However, the fast, highly sensitive, and versatile fluorescent probe still remains a tough challenge among current reports. Herein, we developed a novel aggregation-induced emission (AIE) fluorescent probe TPE-PN for specifically sensing SO2 derivatives with high sensitivity (150 nmol/L) and rapid response time (10 s) based on intramolecular charge transfer (ICT) mechanism. And the fluorescence at 575 nm decreased tremendously with 31-fold after the probe was treated with HSO3-. Employing the probe, the accurate analysis of HSO3- was successfully realized in food samples, cells, plant tissues, and zebrafishes. Furthermore, we successfully demonstrate the eruption of SO2 derivatives within plant during drought and salt stress processes. Therefore, probe TPE-PN illustrates significant potential for applications in food analysis and monitoring of SO2 derivatives levels in biological systems under stress conditions.