4-Aminohippuric Acid-functionalized Carbon Nanotubes for Stripping Voltammetric Determination of Copper(II) Ions

Abstract

In this study, we have demonstrated that 4-aminohippuric acid (AHA) can be coupled to acid-treated multiwalled carbon nanotubes (MWNTs) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) and assembled as AHA-MWNT composites. These functionalized MWNTs can be used for modification of glassy carbon electrode and applied for determination of copper(II) ions. The electrochemical method was based on preconcentration of copper ions onto an electrode surface and then their anodic stripping voltammetric determination. The analytical curve for Cu(II) ions covered the linear range varying from 1.0 up to 230.0 µg L⁻¹. The limit of detection was found to be 0.4 µg L⁻¹, while the relative standard deviation at 5.0 and 200.0 µg L⁻¹ were 1.5 and 1.1%, respectively. Most of the coexisting ions had little or no effect on the determination of copper(II). The obtained results suggest that the proposed method can be applied as a simple and efficient alternative way for the determination of copper ions which have good accuracy in real samples such as human hair and natural waters.