Development of a ruthenium(II) complex-based luminescence probe for detection of hydrogen sulfite in food

摘要

Development of new methods for rapid and effective detection of hydrogen sulfite is of great importance in the studies of this species in food samples. In this contribution, a ruthenium(II) complex-based luminescence probe, Ru-CHO, was developed for fast, highly sensitive and selective recognition and detection of hydrogen sulfite. Ru-CHO was found to be weakly luminescent due to the intramolecular charge transfer dominated by the strong electron withdrawing aldehyde groups. In the presence of hydrogen sulfite, the aldehyde groups in Ru-CHO can specifically react with hydrogen sulfite, which results in the formation of a new ruthenium(II) complex Ru-SO, to lead to the remarkable luminescence enhancement. The recognition reaction was found to be completed in a few seconds, and the dose-dependent increase in luminescence intensity showed good linearity against the hydrogen sulfite concentration, suggested the availability of Ru-CHO for the rapid quantification of hydrogen sulfite in aqueous media. Hydrogen sulfite promoted reaction of Ru-CHO was confirmed by ESI-MS and H-1 NMR analysis, and the photophysical properties, luminescence changes and the electronic transitions in Ru-CHO and Ru-SO were validated by density functional theory (DFT)/time-dependent DFT (TDDFT) calculations. Ru-CHO was successfully used for the quantitative detection of hydrogen sulfite in wine and sugar samples, which validated the practical applicability of Ru-CHO as a luminescence probe for the detection of hydrogen sulfite in food samples.