Detection of L-nicotine with dissipation mode quartz crystal microbalance using molecular imprinted polymers

Synthetic materials with imprinted nanocavities can act as highly selective tailor-made artificial receptors. Implementing these materials in a piezoelectric sensing device can offer fast and straightforward detection together with high sensitivity. L-nicotine, a major addictive substance in cigarettes is used as target molecule. The synthetic receptors for L-nicotine are made via the molecular imprinting technique. The target molecule is added to a monomer mixture containing initiator and this mixture is polymerized with heat. Subsequently, microparticles are obtained by crushing the bulk molecular imprinted polymers (MIPs), which are then immobilized on thin films of polyvinyl chloride. Using Quartz crystal microbalance, L-nicotine could be detected in the submicromolar range and the selectivity of the sensors was verified by reference measurements with L-cotinine. The effectiveness of the sensor was also tested for different aqueous fluids at different pH. It was found that MIPs bind 4.03 times more L-nicotine than non-imprinted polymer in water and 1.99 times more in 0.1× phosphate buffer saline at pH 9.