Water-compatible molecularly imprinted polymers prepared using metal–organic gel as porogen

Abstract

A novel water-compatible approach suitable for molecular imprinting was described, based on the use of a metal–organic gel (MOG) as porogen. The MOG was synthesised by combining Fe(NO₃)₃ and benzene-1,3,5-tricarboxylic acid and used to prepare molecularly imprinted polymer (MIP) containing imprints of levofloxacin with methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EDMA) as crosslinkers. Scanning electron microscopy indicated that the MIP and NIP comprised porous microspheres with the sizes from 400 to 800 nm. In contrast, the MIP and non-imprinted polymer (NIP) prepared in the porogen without MOG showed the clusters of polymer rather than beads. In addition, the surface area of the MOG-based MIPs was an order of magnitude larger than that of the MIP without MOG. A detailed study of adsorption experiments confirmed that the MOG-based MIPs showed good recognition ability in pure water. Polymerization variables, e.g., type of metal ion and coordinating solvents to form MOGs, on the imprinting effect was also investigated. As a conclusion, this approach based on MOG is simple and especially valuable for the domains of the preparation of water-compatible MIPs.