Dual-mode fluorescence and colorimetric bimodal sensing of Baijiu based on the peroxidase activity of CDs@MOF

Baijiu represents the pinnacle of traditional Chinese culinary culture. The role of Baijiu in rituals, banquets, dishes, healthcare, and numerous other areas is evident in various literary works. The reduction of redox-active compounds (e.g., phenols and organic acids) critically modulates the flavor complexity, aroma evolution, and overall quality of Baijiu. Therefore, the present work focuses on Baijiu and the reducing substances in it. In this study, CDs@ZrFe-MOF and three distinct catalase nanase substrates (ABTS, OPD, and TMB) were employed to create fluorescence and colorimetric dual-mode sensor arrays. Oxidation of the enzyme substrate into an appropriate oxidation substrate was facilitated by CDs@MOF in the presence of H₂O₂. The reducing substance effectively inhibited the formation of the oxidation substrate, resulting in alterations in fluorescence and UV intensities. The dual-mode sensor array was found to be effective in detecting 15 different types of reducing chemicals. Furthermore, the colorimetric and fluorescence sensor array demonstrated exceptional capability in detecting 19 different types of Luzhou-flavor liquor samples, obtaining flawless recognition results. This study will provide an accurate and rapid method for differentiating different types of Baijiu.