Dithionite remained in the foodstuff may pose a great threat to the health of consumers. Three xanthylium-based probes were synthesized and their responses to dithionite were explored. Probe could respond to dithionite selectively in PBS buffer (15% DMSO, 10 mM, pH = 7.4). Upon the addition of dithionite, the fluorescent emission of at 684 nm dropped quickly (within 10 s) and the fluorescence decline was proportional to the concentration of dithionite (0–7.0 μM). The limit of detection was determined to be 0.139 μM. Then, the sensing mechanism was tentatively presented and the structure of resulted adduct () which was the reaction product of and dithionite via a Micheal addition reaction followed by an oxidation reaction was verified. Moreover, white granulated sugar was subjected to the standard spike experiments and the results demonstrated a great potential of for the quantitative monitoring of dithionite in foodstuffs.

中文翻译：

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使用基于苍基的荧光探针快速检测糖中的连二亚硫酸钠

食品中残留的连二亚硫酸盐可能对消费者的健康造成很大威胁。合成了三种基于苍基的探针，并探讨了它们对连二亚硫酸盐的响应。探针可以选择性地响应 PBS 缓冲液（15% DMSO，10 mM，pH = 7.4）中的连二亚硫酸盐。添加连二亚硫酸盐后，684 nm 处的荧光发射迅速下降（10 秒内），并且荧光下降与连二亚硫酸盐的浓度（0-7.0 μM）成正比。检测限确定为 0.139 μM。然后，初步提出了传感机理，并验证了所得加合物（）的结构，该加合物是与连二亚硫酸盐通过迈克尔加成反应和氧化反应的反应产物。此外，对白砂糖进行了标准加标实验，结果证明了定量监测食品中连二亚硫酸盐的巨大潜力。