Tracking the chemical surface properties of racemic thalidomide and its enantiomers using a biomimetic functional surface on a quartz crystal microbalance

Abstract

ABSTRACTWe present details of the chemical surface properties of the molecularly imprinted polymer (MIP) on quartz crystal microbalance (QCM) for the tracking of the chiral recognition of racemic thalidomide and its (R)‐enantiomer. We investigate the assembly and specific patterns of enantiomer and racemate of thalidomide on the poly(urethane) coating consisted of the synthetic‐estrogen bisphenol A (BPA) on a QCM electrode by infrared spectroscopy and atomic force microscopy (AFM), which confirmed the surface properties of these materials. The BPA present on the surface of the coating layer revealed a positive frequency response for the racemic thalidomide that eventually appeared. This involved a negative shift of 80 Hz for a 200 µg mL−1 racemic thalidomide, and in all cases, a negative shift of 200 Hz for a 100 µg mL−1 (R)‐thalidomide. The affinity constants (Ka) for the racemate adsorbed onto the polymer layer imprinted with (R)‐thalidomide were lower than those for the (R)‐thalidomide. Also, the binding energy involved a different binding process of the chiral forms and indicated that the two enantiomers had a twofold difference in their binding energies. Thus, the advantage of the use of BPA is proven that will function as hydrogen‐bond donors in the enantioselective recognition site of the MIP. The data of functional analysis demonstrated that the biomimetic detection using molecular imprinting turn out to a study of the pharmaceutical effects of a pharmaceutically chiral compound on natural receptor functions. This approach is highly useful that highlight an enhanced understanding of the mechanism of stereochemistry required for biological controls. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42309.