Capacitive sensing of an amphetamine drug precursor in aqueous samples: Application of novel molecularly imprinted polymers for benzyl methyl ketone detection.

Highly selective molecularly imprinted polymers (MIPs) towards benzyl methyl ketone (BMK) were synthesized for application as recognition elements in a capacitive sensor. A computational approach was employed to select the most appropriate monomers and cross-linkers. Using the selected compounds, different polymerization techniques and protocols were compared in order to study the effect on the MIP performance and characteristics. MIPs synthesized by bulk polymerization using itaconic acid and 1-vinylimidazole as monomers and p-divinylbenzene as cross-linker possess the highest affinity towards the target analyte. Prior to capacitive analysis, the developed particles were immobilized on the surface of gold transducers using tyramine as a linker. The validity of the developed sensor was checked by the BMK detection in spiked tap water and real water samples. A linear working range from 50 to 1000 µM was found while the limit of detection (LOD) was determined to be 1 µM in tap water. To the best of our knowledge, both the developed MIPs towards BMK and the electrochemical sensor for its detection have not been published or marketed to date.