A Novel Acid-Sensitive Colorimetric and Fluorescence Dual Signal Sensor Array for Baijiu Detection

In this work, based on the degradation of rhodamine B (RhB) and rhodamine 6G (R6G) with the catalysis of MnO 2 nanosheets (MnO 2 NSs) under acidity condition, a colorimetric and fluorescence dual signal sensor array was developed for Baijiu discrimination. Rhodamine B and rhodamine 6G present characteristic UV-vis absorption peaks and fluorescence emission peaks at specific wavelength. MnO 2 NSs could induce the degradation of rhodamine B and rhodamine 6G and weaken the intensity of UV-vis and fluorescence. In the presence of organic acids or Baijiu, the degradation of dyes accelerated and the optical signal could be further weakened. Owing to the various of acidity, the sensor array exhibited different responses to organic acids and Baijiu, resulting in unique fingerprint maps. With the method, 8 kinds of organic acids and formic acid-acetic acid mixture samples were successfully recognized. In addition, 12 kinds of Baijiu with different flavor types were identified with 100% accuracy. Notably, 5 other distilled liquors were also successfully discriminated with no misclassifications. The method not only reduces the amount of dyes, but also improves the specificity of the sensor array, demonstrating the potential application prospects of the dual signal sensor array in Baijiu industry.