A Sensitive MOF⊃Dye Hydrogel for Visual Recognition of Fluoroquinolones

Abstract Development of new multi‐ratiometric fluorescence probes has been a popular research field. This approach provides richer and more accurate information for the recognition of different substances which have similar chemical and physical properties. In this work, a ratiometric fluorescence sensor UIO‐66⊃FL/RhB is successfully constructed by incorporating fluorescein (FL) and rhodamine B (RhB) to the UIO‐66. With the addition of fluoroquinolones (FQs), the prepared UIO‐66⊃FL/RhB sensor can be used for the 2D emission‐fingerprint map, the linear discriminant analysis (LDA) and hierarchical clustering analysis (HCA) in recognition the presence of each FQs. The fluorescence probe offers a broad linear range (0‐8 µM) and a low detection limit (3.7 nM) in sensing ofloxacin. In addition, a smartphone‐assisted portable sensing platform and a portable UIO‐66⊃FL/RhB hydrogel test material are constructed successfully for screening before fluorescence detection. This study proposes a novel multi‐ratiometric fluorescence probe, which can recognize different FQs. Besides, the UIO‐66⊃FL/RhB‐based hydrogel beads are construction for screening before the detection of FQs, which established a promising strategy for the simple and accurate discrimination of FQs.