A colorimetric and ratiometric fluorescent probe for rapid, sensitive and visual detection of metabisulfite in food and living cells

Abstract

Sodium metabisulfite (Na₂S₂O₅) is widely used as a bleaching agent and food preservative. However, excess of S₂O₅²⁻ can irritate and damage the human body. In this study, we report a colorimetric and ratiometric fluorescent probe for visual detection of S₂O₅²⁻. The probe can quantitatively determine S₂O₅²⁻ with high specificity and sensitivity, fast response (<30 s) as well as a low detection limit (6.8 nM). A 1,4-Michael addition reaction was proposed for the sensing mechanism of this probe, which was confirmed by ¹H NMR and HR-MS spectra. The probe has been successfully utilized to determine S₂O₅²⁻ in food with good recovery, from the remarkable colorimetric and ratiometric fluorescence changes. The probe was also employed to visualize S₂O₅²⁻ in live cells. Furthermore, the probe has been successfully prepared into a portable kit for real-time visual detection of S₂O₅²⁻ in food. Therefore, this probe has great potential application for the detection of S₂O₅²⁻ in food and living cells.