MIP-capped terbium MOF-76 for the selective fluorometric detection of cefixime after its preconcentration with magnetic graphene oxide

Herein, a sensitive and reliable fluorometric probe based on the molecular imprinted polymer capped terbium metal-organic frameworks (MIP@TbMOF-76) was introduced for the measurement of cefixime. The MIP@TbMOF-76 composite was prepared by simple co-polymerization of definite monomers and cross-linkers in the presence of TbMOF-76 as support and cefixime as the model template molecules. After the removing of template molecules, the obtained composite had an intense fluorescence emission corresponding to the terbium emission spectra which undergo a sensible diminution in the presence of cefixime. The prepared MIP@TbMOF-76 indicated a great affinity to adsorb cefixime molecules, which could linearly quench the emission intensity. Moreover, an extraction process using magnetic Fe3O4@SiO2 modified graphene oxide (Fe3O4/GO) was applied for the efficient preconcentration of cefixime from aqueous solution to access its very low concentrations. Based on this procedure, an ultrasensitive and selective probe was designed for cefixime. After optimization of key factors, a calibration graph was achieved in the concentration range of 0.8–90 ng mL−1 cefixime, with a detection limit (3 s) of 0.34 ng mL−1. The developed probe had a good precision (RSD%