SELECTIVE NANOSENSING OF COPPER (II) ION USING L-LYSINE FUNCTIONALIZED GOLD CYSTEAMINE SELF-ASSEMBLED MONOLAYER

Abstract

Fabrication of a cysteamine (CA) self-assembled monolayer (SAM) modified gold electrode insitufunctionalized with L-Lysine (Lys) is presented and described. The fabricated electrode was used forhighly selective and sensitive accumulation and the determination of copper ions (Cu2+) in a nanomolarconcentration. Techniques like cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)with an external redox probe (p-Benzoquinone) were used to investigate the layer-by-layer self assemblymodification on a gold electrode, monolayer structure and the ion permeation through it. The differentialpulse voltammetric (DPV) method was used for determination of Cu2+. The results indicated that DPV peakscurrents have a linear relationship with pCu in the concentration range of 1.0×10-12 - 1×10-6 M, with acorrelation coefficient of 0.9982. The detection limit could be estimated 1.2×10-13 M according to the IUPACrecommendation (3σ).