Amino-functionalized Fe(III)-Based MOF for the high-efficiency extraction and ultrasensitive colorimetric detection of tetracycline

In order to achieve the simultaneous extraction and detection of tetracycline (TC) in milk, the amino--functionalizedFe-based metal-organic frameworks (NH2-MIL-88B) was synthesized via a solvothermal method with Fe3+ and 2-aminoterephthalic acid (NH2-BDC) as precursor. Thanks to the unique structure of NH2-MIL-88B, it could be used to highly effective extract of TC in milk. More interestedly, the introduced -NH2 could react with -OH from TC by a hydrogen-bonding interaction to cause the electronic interactions that en-hances the peroxidase-like activity of NH2-MIL-88B, which result in the enhancement of Fenton reaction by the transfer of the electron between TC and NH2-MIL-88B. Under the optimal testing conditions, the linear absorbance response is well correlated with the TC concentration range of 50-1000 nM, which can reach a low LOD of 46.75 nM. Besides, the sensor exhibits excellent selectivity to TC, and the proposed strategy can also be applied to milk with good recovery (83.33-107.00%). Finally, the NH2-MIL-88B and cellulose acetate (CA) are combined to form nanozyme hybrid membranes through the non-solvent induced phase separation method, which can be used to prepare point-of-care testing (POCT) for rapid and in-situ detection of TC.