Synthesis and characterization of molecularly imprinted polymers with metallic zinc center for enrofloxacin recognition

Abstract

A molecularly imprinted polymer with a metallic center (MIPc) was prepared and characterized. The template molecule for MIPc was a complex [Zn(Aza-f)(Enr)]NO3⋅H2O, Com, based on the ligands: enrofloxacin (Enr) and azabis(oxazoline) functionalized with styrene. Com was characterized before preparing MIPc. Moreover, the polymer prepared via non-covalent (MIPe) was prepared using Enr as the template molecule while no template molecules were used to prepare the non-imprinted polymer (NIP).MIPc was characterized using different spectroscopic techniques. In addition, the polymer molecular recognition capacity was studied by using rebinding kinetic studies. The kinetics shows that MIPc reach the equilibrium before the MIPe and NIP and the amount of Enr adsorbed is approximately 5times higher that MIPe and NIP.Scatchard plots analysis for NIP, MIPe and MIPc shows Kd=0.4768, 0.020, 0.0067 (mmolL−1) respectively. In comparison with the MIPe the binding affinity is nearly 100times higher taking into account the high affinity sites. The selectivity of MIPc for Enr was higher than that for ofloxacin or flumequin, isotherms were fit to the Langmuir–Freundlich model, and the Enr showed a value of Ko=21.38mM−1, while the ofloxacin had a value of 2.2×10−8mM−1 and the flumequin of 1.6×10−5mM−1.