A triple-channel fluorescent sensor array based on R6G@Eu-MOF for baijiu discrimination

A triple-channel R6G@Eu-MOF fluorescent probe was developed for multi-signal sensing. • A six-channel sensor array was constructed using two solvent-dependent fluorescence responses. • The sensing mechanism involved hydrogen bonding and Eu excited-state/O–H oscillator coupling. • The platform enabled discrimination of organics, Baijiu, and other distilled liquors. Rapid discrimination of Baijiu is of interest for preliminary quality assessment and authenticity screening. In this work, a single-probe multi-channel fluorescent sensor array was developed based on R6G@Eu-MOF for Baijiu discrimination. By integrating rhodamine 6G (R6G) and Eu 3+ into one MOF platform, R6G@Eu-MOF provided three intrinsic emission signals at 550, 594, and 615 nm. Unlike conventional sensor arrays that usually require multiple sensing materials, this strategy expanded the three emission outputs into a six-channel response pattern by using DMF and ethanol as two distinct probe-dispersing microenvironments. Owing to differences in polarity, hydrogen-bonding ability, and chemical composition, different analytes induced characteristic fluorescence-response fingerprints. The response behavior was attributed to hydrogen-bonding interactions, modulation of the R6G microenvironment, coupling of the Eu excited state with O H oscillators, and possible inner filter effects. Based on this strategy, 16 representative organics and EtOH-water mixtures with different ratios were effectively discriminated. Under the current experimental conditions, 16 representative commercial Baijiu samples were clearly separated in the LDA analysis, and blind-sample validation showed a recognition accuracy of 90.6%. The array was also extended to other distilled liquors. This work provides a simple and material-efficient fluorescent-array strategy for pattern-recognition analysis of complex liquor samples. Scheme 1 Schematic illustration of R6G@Eu-MOF fluorescent sensor array for Baijiu discrimination. Download: Download high-res image (150KB) Download: Download full-size image