Highly sensitive nanostructure voltammetric sensor employing Pt/CNTs and 1-butyl-3-methylimidazolium hexafluoro phosphate for determination of tryptophan in food and pharmaceutical samples

Abstract

A novel, sensitive, selective and simple method for the direct and quantitative determination of l-tryptophan (Trp) was proposed in this work. Pt/CNTs nanocompoite made by polyol technique, were used to modify ionic liquid carbon paste electrode (CPE) without any treatment to study the electrochemical behaviors of the Trp using cyclic voltammetry (CV) and chronoamperometry (CA) and square wave voltammetry (SWV) methods. The results demonstrated that the 1-butyl-3-methylimidazolium hexafluoro phosphate (([C4mim]-[PF6])) Pt/CNTs modified carbon paste electrode ([C4mim]-[PF6]/Pt/CNTs/CPE) exhibited high catalytic activity and analytical performance towards the electro-oxidation of Trp. The linear oxidation response range and limit of detection were found to be 0.1–400μM and 0.04μM, respectively. The [C4mim]-[PF6]/Pt/CNTs/CPE was successfully applied for the voltammetric determination of Trp in food and pharmaceutical samples.