A supersensitive sensor for rutin detection based on multi-walled carbon nanotubes and gold nanoparticles modified carbon paste electrodes

Abstract

A new voltammetric sensor was designed by covering a layer of gold nanoparticles (AuNPs) on a carbon paste electrode that was pre-mixed in some multi-walled carbon nanotubes (MWCNT). This sensor exhibited super sensitive detection of the electroactive flavonoid rutin due to the large surface area and good conductivity of MWCNT and AuNPs. Cyclic voltammetry curves at various scan rates and pH were recorded to investigate the redox properties of rutin. Further experiments demonstrated that the oxidative peaks increased linearly with rutin concentrations in the ranges of 4.0 × 10⁻¹⁰ to 1.0 × 10⁻⁸ mol L⁻¹ and 2.0 × 10⁻⁸ to 1.0 × 10⁻⁶ mol L⁻¹ with a limit of detection of 4.0 × 10⁻¹¹ mol L⁻¹. The method was successfully applied to detect rutin in medicine tablets with satisfactory results.