Designing and fabrication of new molecularly imprinted polymer-based potentiometric nano-graphene/ionic liquid/carbon paste electrode for the determination of losartan

In this study, a novel losartan molecularly imprinted polymer was synthesized and used as a sensing agent in a sensing layer of the new modified potentiometric nano-graphene/carbon paste electrode incorporated with graphite powder, synthesized graphene nano-sheets and an ionic liquid, as the conducting binder, for the selective determination of losartan. Methacrylic acid as functional monomer, ethylene glycol dimethacrylate as a cross linker,.2-2'-azoisobutyronitrile as an initiator and chloroform as polymerization solvent were used. The characteristic of the synthesized molecularly imprinted polymer were investigated by Fourier transform infrared analysis and scanning electron microscopy. The molecularly imprinted polymer-modified electrode exhibited a Nernstian response (59.64 +/- 0.20 mV decade(-1)) in a wide linear dynamic range of 3.00 x 10(-9) to 1.00 x 10(-2)M with a lower detection limit of 1.82 x 10(-9)M. The suggested potentiometric sensor demonstrated a fast response time of similar to 6 s, a high performance, fairly high selectivity over some interfering compounds and a satisfactory long-term stability (more than 3 months). It was successfully applied for the highly sensitive determination of losartan in pharmaceutical products and urine samples with satisfactory results. (C) 2015 Elsevier B.V. All rights reserved.