Formulation of Cocaine-Imprinted Polymers Utilizing Molecular Modelling and NMR Analysis

Abstract

Molecular imprinted polymers (MIPs) have distinctive features that make them attractive as an inexpensive, reusable, and robust field-based detection system for illicit substances. Optimizing MIP performance is traditionally attained by the synthesis and evaluation of a plethora of individual formulations. A non-covalently imprinted polymer for cocaine has been prepared using a commercially available molecular modelling package (Spartan 02) to predict energetically favourable monomer–template interactions between the target (T) and two different functional monomers (FM)—methacrylic acid (MAA) and 4-vinylpyridine (4VP). NMR studies undertaken to assess target–monomer behaviour in solution were in good agreement with the computational data. MIPs involving three target-to-functional monomer ratios (1 : 2, 1 : 6, and 1 : 14) were prepared and evaluated. Target rebinding was found to be most favourable in the 1 : 2 formulation with a target-selective binding of 0.48 ppm and an imprinting factor (I) of 2.8 obtained for 10 mg of test polymer.