High-performance near-infrared fluorescence probe for fast and specific visualization of harmful sulfite in food, living cells, and zebrafish

[Display omitted] •DCQN showed fast, sensitive and specific NIR fluorescence turn-on response to sulfite.•Sulfite in food could be visually detected by DCQN in term of chromogenic reaction.•DCQN could be used for tracking and imaging of sulfite in cells and zebrafish.•DCQN-incorporated agar hydrogel as a portable device could on-site detect sulfite. Excessive sulfite is harmful to human health. To monitor the sulfite level in food, living cells, and organisms, we herein present a high-performance near-infrared (NIR) fluorescent probe DCQN that exhibits chromogenic and NIR fluorescence turn-on response towards sulfite with a rapid response time of 4.5 s, unique specificity, a low detection limit of 24 nM, and a large Stokes shift. DCQN was used for the facile and accurate determination of the sulfite level in real food with high sensitivity and good recoveries (93–105%). In particular, the sulfite present in food samples can be in situ visually detected by DCQN in terms of chromogenic reaction along with fluorescence turn-on indicator. Moreover, DCQN was incorporated into agar hydrogel to serve as a convenient, cheap and portable device for the fast and visual on-site detection of sulfite in food. Furthermore, DCQN was used to achieve in situ tracking and imaging of sulfite in MCF-7 cells and zebrafish with a high contrast ratio and high sensitivity.