A novel acid-sensitive quantum dot sensor array for the identification of Chinese baijiu

The organic acid content plays important roles in the flavor and taste of Chinese baijiu. Developing a detection and discrimination technique for organic acids and employing it as a basis in baijiu classification has great practical significance. We employed 3 kinds of acid-sensitive quantum dots (QDs) to construct a fluorescence sensor array for the detection and identification of organic acids in baijiu. We report the first directional use of array sensing detection technology for the evaluation of organic acids in baijiu. Linear discriminant analysis (LDA) was successfully employed to evaluate the ability of the as-developed sensor array to classify organic acids. The Euclidean distance analysis was introduced to prove the provided sensor array possesses good quantitative detection. On this basis, our sensor array was successfully applied to distinguish 16 kinds of baijiu samples. The results were supported by principal component analysis (PCA), LDA, and systematic cluster analysis (HCA). Furthermore, Pearson correlation results indicated a strong correlation between the detection results and the organic acids in baijiu. This simple and accurate method shows potential for quality control and detection in baijiu factories and markets.