Dual-ligand lanthanide metal-organic framework based ratiometric fluorescent platform for visual monitoring of aminoglycoside residues in food samples

Herein, a dual-emission Eu metal-organic framework (Eu-MOF) is prepared and used as the ratiometric fluorescence probe for ultrasensitive detection of aminoglycoside antibiotics (AGs). Due to the strong hydrogen bond interactions between AGs and Eu-MOF, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF with the addition of AGs, thus a good linear relationship with the logarithm of AGs concentrations from 0.001 to 100 μg/mL can be established for quantitative analysis. Good sensitivity with the detection limit of 0.33 ng/mL for apramycin, 0.32 ng/mL for amikacin and 0.30 ng/mL for kanamycin is achieved. The proposed assay demonstrates good selectivity and applicability for determination of AGs in real milk and honey samples. The Eu-MOF materials are further fabricated as fluorescent test papers for facile visual detection. The as-established ratio fluorescence platform offers a portable and economical way for rapid monitoring AGs residues in complex food samples. Synopsis: The Eu-MOF is composed of two ligands of 2-aminoterephthalic acid (BDC-NH2) and 1,10-phenanthroline (phen) that coordinated to Eu3+, which emits blue fluorescence at 434 nm and red fluorescence at 613 nm under 365 nm excitation. In the presence of AGs, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF, thus detection of AGs is achieved by using Eu-MOF as ratiometric fluorescence probe, and the visual fluorescence variation from red to purple to blue can be readout by naked eyes using Eu-MOF loaded test paper. [Display omitted] •Eu-MOF ratiometric fluorescence probe is designed for ultrasenstive AGs detection.•Detection mechanism is based on enhancing the ICT effect of Eu-MOF by adding AGs.•Eu-MOF test paper is further fabricated as portable sensor for visual analyzing AGs.•It offers an economical way for rapid detection of AGs residues in real food samples.