Study on the identification of strong-aroma baijiu series using a colorimetric-fluorescence dual-mode sensing array based on CuMn-His@NCDs

Accurate identification of strong-aroma baijiu is crucial for market regulation. This study constructed a dual-mode colorimetric-fluorescence sensor array based on CuMn-His@NCDs nanocomposites. Under neutral conditions, the composite exhibits laccase-like activity, while under acidic conditions it demonstrates oxidase-like activity, catalyzing 3,3′,5,5′-tetramethylbenzidine (TMB), o -phenylenediamine (OPD), and 4-aminoantipyrine (4-AP) to produce distinct signals. A six-channel array enabled multidimensional output. For the training set, the array achieved 100% classification accuracy in identifying 13 phenolic and 8 non-phenolic compounds using principal component analysis (PCA), linear discriminant analysis (LDA), and hierarchical cluster analysis (HCA). The array successfully distinguished 18 similar strong-aroma baijiu varieties, achieving 100% training accuracy, while blind prediction tests on unknown samples yielded 88.8% accuracy. The sensor array exhibits excellent repeatability (relative standard deviation (RSD) < 5%) and stability (response retention >81.58% after 15 days). This sensor holds significant potential for baijiu authentication.