A portable smartphone-assisted Tb/Eu-MOF agar slice probes for the visual detection of fluoroquinolones

The extensive use of fluoroquinolones (FQs) leads to food residues, which present a significant risk to human health. A portable smartphone-assisted detection platform based on Tb/Eu-MOF nanomaterial was established for the detection of FQs, with the enrofloxacin (ENR) serving as a representative sample. Five Tb/Eu-MOFs with different bimetallic proportions were synthesized, and the Tb/Eu-MOFs (3:1) served as the optimal sensing element. The Tb/Eu-MOF nanomaterial suspension demonstrated a color change from orange-red to pale yellow as a result of fluorescence resonance energy transfer with ENR, attaining a LOD of 0.004 μM and a broad linear range of 0.005–25 μM. The Tb/Eu-MOF was incorporated into an agar slice and coupled with a smartphone for detection to improve portability. A smartphone-based agar slice platform was developed with a linear range of 5–150 μM and a LOD of 4.7 μM. This detection platform offers an innovative, low-cost and portable approach for FQs detection.