Fast and highly selective detection of acetaldehyde in liquor and spirits by forming aggregation-induced emission luminogen

Acetaldehyde is one of the most important flavor constituents in liquor and spirits, which is the major origination of its spicy taste. However, as a human carcinogen, excessive intake of acetaldehyde is harmful to health. In this work, a fluorescence sensor of 5-methoxycarbonylsalicylaldehyde hydrazone (1) was developed to achieve a fast and highly selective response for acetaldehyde. Mechanism study showed that when 1 combined with acetaldehyde in aqueous solution at neutral pH, an aggregation-induced emission luminogen (AIEgen) was produced, resulting in a "turn-on" fluorescence response. Compared to gas chromatography, the traditional detective method for acetaldehyde in liquor and spirits, fluorometry using 1 has a number of advantages including simplicity, quick response and capability of real-time detection. More important, the detections of acetaldehyde in real liquor and spirits samples were successfully achieved.