Synergic effect of Pt-Co nanoparticles and a dopamine derivative in a nanostructured electrochemical sensor for simultaneous determination of N-acetylcysteine, paracetamol and folic acid

A carbon paste electrode (CPE) was modified with Pt-Co nanoparticles and 2-(3,4-dihydroxyphenethyl)isoindoline-1,3-dione (3,4-DHPID) and then used for determination of N-acetylcysteine (N-AC) in the presence of paracetamol (PC) and folic acid (FA). The Pt-Co nanoparticles were synthesized by the polyol method and characterized by X-ray diffraction, energy dispersive X-ray analysis and transmission electron microscopy. The modified CPE displays good electrocatalytic activity towards the electrooxidation of N-AC in solution of pH 7.0. It was applied to the determination of N-AC in the presence of PC and FA (with well separated signals peaking at 0.2, 0.55 and 0.86 V vs. Ag/AgCl) by using square wave voltammetry. The peak currents are linearly dependent on the concentrations of N-AC, PC and FA in the respective ranges from 0.07 to 500, 1.0 to 850, and 2.0 to 550 mu mol center dot L-1, with detection limits of 0.009, 0.6 and 0.8 mu mol center dot L-1. The modified CPE was applied to the determination of N-AC, PC and FA in (spiked) pharmaceutical and biological samples.