Nanomolar Detection of Dopamine at ZnO/Graphene Modified Carbon Paste Electrode

Abstract

In the present work, we demonstrate the electrocatalytic activity of few layer graphene and wurzite ZnO nanoparticles modified carbon paste electrode towards the oxidation of dopamine. Cost effective, simple and fast solution combustion synthesis was utilized for the synthesis of pure crystalline phase of wurzite ZnO nanoparticles. The commercial few layer graphene and ZnO modifiers were uniformly incorporated into the carbon paste matrix by simple bulk modification technique. The modified electrode enhanced the current sensitivity and resolved the DA peak from interfering molecules such as ascorbic acid and uric acid. The electrode has a detection limit of 60 nM having a wide linear dynamic range of 80 μM–80 nM. The fabricated sensor has excellent stability and reproducibility. The sensor was successfully utilized for the quantification of dopamine in blood serum.