Surface-engineered Au@Pt nanoparticles-based colorimetric/fluorescent dual-mode three-channel sensor array: Discrimination of light aroma-type Baijiu with variable qualities.

The development of light aroma-type Baijiu (LAB) industry proposes a growing need for developing rapid and accurate discrimination method for the quality control of LAB. This study innovatively constructed a dual-mode three-channel sensor array based on the gold/platinum nanoparticles (Au@Pt NPs) with surface engineering. In this case, two colorimetric sensor channels based on ascorbic acid/para-aminophenol-chloroauric acid-nanozyme (AA/ pAP-HAuCl₄-Au@Pt NPs) and one fluorescent sensor channel based on nanozyme‑hydrogen peroxide-o-phenylenediamine (Au@Pt NPs-H₂O₂-OPD) were established. Experimental results demonstrate the colorimetric and fluorescence mode can accurately quantify four organic acids and three aldehydes in Baijiu, respectively. Samples including 17 different years and 9 different production processes of basic liquors of LAB, 48 different price gradients of commercial LAB, and adulterated LAB were analyzed. Discrimination with an accuracy exceeding 96% by Linear Discriminant Analysis, Hierarchical Cluster Analysis, and leave-one-out cross-validation was achieved. The dual-mode three-channel sensor array is characterized by simplicity, rapidity and accuracy, providing a new idea for the quality discrimination and market regulation of Baijiu.