A novel fluorescent sensor array to identify Baijiu based on the single gold nanocluster probe

Baijiu occupies a vital position in Chinese food and China's market. Strict evaluation of Baijiu is highly demanded. In this study, we constructed a novel fluorescent sensor array based on the single glutathione-protected gold nanoclusters (AuNCs) probe for the detection of organic acids and Baijiu. The fluorescence of AuNCs was simply modulated by three metal ions (Cu²⁺, Mn²⁺, and Ag⁺), and formed new complexes as sensing elements. These four sensing elements responded variously to nine organic acids, and further chemometric analysis results allowed for the classification and quantification of acids. Moreover, the sensor array successfully identified 21 Baijiu samples of different brands among 11 aroma types. It could also distinguish Baijiu of different qualities as well as pure Baijiu from its adulterations and showed high selectivity among multiple interfering drinks. The results demonstrated that the AuNCs-based sensor array has considerable potential for quality monitoring of Baijiu.