Poly (amido amine) dendrimer/silver nanoparticles/multi-walled carbon nanotubes/poly (neutral red)-modified electrode for electrochemical determination of paracetamol

Abstract

The electrochemical determination of paracetamol (PA) was investigated using a layer by layer architecture of poly (amido amine) dendrimer (PAMAM)/silver nanoparticles (AgNPs)/multi-walled carbon nanotubes (MWCNTs)/poly (neutral red) (PNR)-modified electrode. The electrochemical behavior of PAMAM/AgNPs/MWCNTs/PNR-modified electrode was investigated by cyclic voltammetry and a pair of redox peaks appeared with the peak to peak separation (ΔEp) of 0.17 V in phosphate buffer solution (PBS) of 0.1 M at pH 7.0. The modified structure was examined for the determination of PA in a 0.1 M PBS of pH 7.0. The PAMAM/AgNPs/MWCNTs/PNR-modified electrode was found to possess good electrocatalytic activity toward PA oxidation which was observed at a lower oxidation potential around 0.4 V with a higher current response. The electrochemical oxidation of PA by PAMAM/AgNPs/MWCNTs/PNR-modified electrode involves a two-proton and two-electron processes. In the optimal conditions with square wave voltammetric measurement, a linear relationship between the catalytic current and PA concentration was obtained in the range from 0.16 to 2000 μM with a detection limit of 0.053 μM (S/N = 3). The coexisting substances exhibited no interference and PAMAM/AgNPs/MWCNTs/PNR-modified electrode was applied to the determination of PA in human urine and pharmaceutical (calpol and dolo-650) samples and the results were found to be satisfactory.