Molecularly imprinted polymers for the detection of caffeine in water.

摘要

This work investigates the potential of Molecularly Imprinted Polymers (MIPs) for the detection of caffeine in water samples. Different polymerization techniques were explored; namely free-radical bulk, miniemulsion and precipitation polymerization. Building the adsorption isotherms allowed determining the rebinding capacities of the resulting polymers (binding constant and number of sites). Using the nanoparticles prepared by precipitation polymerization in acetonitrile, new analytical techniques were developed. The latex was analyzed directly by High Performance Liquid Chromatography allowing fast template quantification in water samples. In addition, the nanoparticles were coated on a 5MHz microbalance quartz crystal. The bi-Langmuir isotherm allowed computing the mass uptakes at the sensor's surface and suggested that as little as 0.1 ng of caffeine could be detected.