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

Document Type: Regular Paper

Authors

1 Department of Chemistry, Islamic Azad University, Science and Research Branch, P.O. Box: 145-775, Tehran, I. R. of Iran

2 Advanced Institute of Technology, Iranian Research Organization for Science and Technology (IROST), P.O. Box: 15815-3538, Tehran, I. R. of Iran

Abstract

Fabrication of a cysteamine (CA) self-assembled monolayer (SAM) modified gold electrode insitu
functionalized with L-Lysine (Lys) is presented and described. The fabricated electrode was used for
highly selective and sensitive accumulation and the determination of copper ions (Cu2+) in a nanomolar
concentration. 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 assembly
modification on a gold electrode, monolayer structure and the ion permeation through it. The differential
pulse voltammetric (DPV) method was used for determination of Cu2+. The results indicated that DPV peaks
currents have a linear relationship with pCu in the concentration range of 1.0×10-12 - 1×10-6 M, with a
correlation coefficient of 0.9982. The detection limit could be estimated 1.2×10-13 M according to the IUPAC
recommendation (3σ).

Keywords