A Sensitive MOF⊃Dye Hydrogel for Visual Recognition of Fluoroquinolones

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.