A nanocomposite consisting of carbon nanotubes and gold nanoparticles in an amphiphilic copolymer for voltammetric determination of dopamine, paracetamol and uric acid

The amphiphilic copolymer poly(vinylbenzyl thymine-co-styrene-co-maleic anhydride) (PSVM) was synthesized by radical copolymerization of styrene, vinylbenzyl thymine, and maleic anhydride. Its chemical structure was proven by using H-1 nuclear magnetic resonance spectroscopy. PSVM was used as a host to prepare a composite consisting of carbon nanotubes and gold nanoparticles by in-situ reduction. The morphology of the nanocomposites was studied by transmission electron microscopy. A glassy carbon electrode coated with this composite is shown to be a viable sensor for the determination of dopamine (DA), paracetamol (PAT) (both at a pH value of 7), and uric acid (UA) (at pH 6). Two linear relationships exists between amperometric current and analyte concentrations. For DA, the linear analytical ranges are from 0.1 to 200 mu M and from 200 to 1000 mu M. For PAT, the ranges are from 0.1 to 200 mu M and from 200 to 1000 mu M. For UA, the ranges are from 0.05 to 1000 mu M. The respective limits of detection (for S/N = 3) are 56, 27 and 50 nM. The sensor is highly sensitive, stable, reproducible, and selective.