Colorimetric and near-infrared spectrophotometric monitoring of bisulfite using glyoxal modified chromenylium-cyanine chemosensor: Smartphone and paper strip applications for on-site food and beverages control

Abstract

Detection of bisulfite (HSO3-) in food and beverages has vital importance because the excessive amount leads to ill effects on the human body. Colorimetric and fluorometric chromenylium-cyanine-based chemosensor CyR was synthesized and applied for high selective and sensitive analysis of HSO3- in red wine, rose wine and, granulated sugar with high recovery ranges and very fast response time without any interference from other competitive species. The limits of detection (LOD) for the UV-Vis and fluorescence titrations were found as 11.5 μM and 3.77 μM, respectively. The on-site and very rapid methods based on paper strips and smartphone which depend on the color changes from yellow to green have been successfully developed to analyze HSO3- concentration (10-5-10-1 M for paper strip and 163-1205 μM for smartphone). CyR and the bisulfite-adduct formed in the nucleophilic addition reaction with HSO3- were verified by FT-IR, 1H NMR, and MALDI-TOF results as well as Single-Crystal X-Ray Crystallography for CyR.