A quinolinium-based fluorescent probe for ultrafast detection of bisulfite and its applications in food detection, SO2 gas detection, and cell imaging

Abstract

Sulfur dioxide and its derivatives (HSO₃⁻/SO₃^2-) play a crucial role in maintaining the redox balance of biological systems. Therefore, the development of effective detection methods for sulfur dioxide and its derivatives is of paramount importance. Herein, a novel fluorescent probe, QLN, was designed and synthesized using small molecule quinoline, demonstrating the capacity to recognize HSO₃⁻ through Michael addition reaction. The probe QLN displayed good selectivity and anti-interference capabilities for HSO₃⁻ recognition, effectively operating within a wide pH range (5–9) and exhibiting a rapid response time (<5 s). Practical applications revealed the potential of probe QLN for detecting HSO₃⁻ in living cells and food samples.