Eu<sup>3+</sup>-Doped Anionic Zinc-Based Organic Framework Ratio Fluorescence Sensing Platform: Supersensitive Visual Identification of Prescription Drugs
Wensheng Liu, Yao Huang, Chenhui Ji, Craig A. Grimes, Zerong Liang, Hairong Hu, Qing Kang, Hailong Yan, Qingyun Cai, Yi‐Ge Zhou
Abstract
Advanced techniques for both environmental and biological prescription drug monitoring are of ongoing interest. In this work, a fluorescent sensor based on an Eu 3+ -doped anionic zinc-based metal–organic framework (Eu 3+ @Zn-MOF) was constructed for rapid visual analysis of the prescription drug molecule demecycline (DEM), achieving both high sensitivity and selectivity. The ligand 2-amino-[1,1′-biphenyl]-4,4′-dicarboxylic acid (bpdc-NH 2 ) not only provides stable cyan fluorescence (467 nm) for the framework through intramolecular charge transfer of bpdc-NH 2 infinitesimal disturbanced by Zn 2+ but also chelates Eu 3+, resulting in red (617 nm) fluorescence. Through the synergy of photoinduced electron transfer and the antenna effect, a bidirectional response to DEM is achieved, enabling concentration quantification. The Eu 3+ @Zn-MOF platform exhibits a wide linear range (0.25–2.5 μM) to DEM and a detection limit (LOD) of 10.9 nM. Further, we integrated the DEM sensing platform into a paper-based system and utilized a smartphone for the visual detection of DEM in water samples and milk products, demonstrating the potential for large-scale, low-cost utilization of the technology.