A minimalist fluorescent MOF sensor array for Baijiu identification

The beverage industry is in the market tuyere, and grasps the lifeline of the social economy, so it is particularly vital to supervise it. Herein, we report a minimalist fluorescence metal-organic framework (MOF) sensor array for Baijiu identification. The original MOF was modified by rare-earth elements to obtain Eu-MOFs and Tb-MOFs. They exhibited multiple fluorescence characteristic peaks in the range of 400-700 nm when excited at 325 nm. The organic molecules in the Baijiu reacted with Eu-MOF and Tb-MOF, affecting the energy transfer of the entire system and the electronic transition of Eu³⁺ and Tb³⁺, which were accompanied by various changes in the fluorescence intensity. For each analyte, a unique fluorescence fingerprint and heat map would be formed, which could be discriminated by pattern recognition. With this method, 11 kinds of organic molecules were identified accurately. A good stepwise bilinear function between the fluorescence intensity and concentrations of ferulic acid was obtained at 0.2-3.13 μM and 6.25-100 μM. Crucially, 16 kinds of Baijius of different brands were accurately identified with an accuracy of 100%. The sensor array showed the advantages of strong maneuverability and fast response, exhibiting good application value in Baijiu detection.