A quinolinium-phenol vinylic conjugated fluorescent probe for H2S detection based on H2S-triggered release of protected group

Development of colorimetric and fluorescent probes capable of selectively detecting H2S has emerged as attractive tools to understand the roles of H2S in various physiological processes and food safety. Here, we show a facile and efficient strategy that involves introducing a quinolinium-phenol vinylic conjugate QLS as a colorimetric and fluorescent probe, based on the principle of H2S-triggered release of protected group (PG). The synthesized probe QLS can efficiently monitor and identify trace amounts of H2S with highly selectivity, sensitivity and Naked-eyed detection (red-shifted ≈170 nm). The sensing mechanism was confirmed by spectral and MS analysis, which showed H2S-triggered release of PG to form labile zwitterionic [QLS-O-], followed by self-immolation and ultimately lead to a neutral quinoline-alkenone conjugate (QLT). Additionally, the QLS-loaded test strips was prepared and applied in practical food samples detection.