Evaluation of some structural characteristics of films with molecular imprints of antibiotics

Abstract

Using scanning force microscopy (SFM), we evaluated some morphological characteristics of molecularly imprinted polymer (MIP) films with imprints of sodium cefuroxime and sodium cefazolin. Morphostructures are most often formed under the influence of internal processes, including non-covalent interactions between templates and the functional monomer. Thus, a polyimide film of a non-imprinted polymer (NP) is characterized by a uniform surface relief, while MIP films exhibit more significant height differences. Thus, during the synthesis of MIPs, the polyimide structure changes, leading to a redistribution of porosity: the number of micropores decreases, and the number of meso- and macropores increases. Probably, micropores corresponding to the structure of template molecules may be present on the inner walls of meso-, macropores and cracks. The use of MIPs in sensor technologies is promising. In the work, two-electrode sensors obtained on a polyimide film by the method of thermal transfer with subsequent chemical etching were used. MIP synthesis was carried out directly on the surface of the electrodes of the amperometric sensors. As was found, the sensitivity of the sensor with the imprinted polymer to cefuroxime and cefazoline is 13.0 and 18.8, respectively, while for non-imprinted polymers these values are 3.0 and 5.0. Despite the fact that the number of micropores in the MIP is less than in pure polyimide, the sensitivity of the MIP sensors is significantly higher. Probably, molecular imprints are formed mainly in the micropores. Therefore, the use of MIPs in sensor systems makes them highly sensitive to template molecules and allows using these devices for selective determination of substances in liquid media.