Detection of Trace Heavy Metal Ions Using Carbon Nanotube- Modified Electrodes

Abstract

A sensitive voltammetric method for detection of trace heavy metal ions using chemically modified carbon nanotubes (CNTs) electrode surfaces is described. The CNTs were covalently modified with cysteine prior to casting on electrode surfaces. Cysteine is an amino acid with high affinities towards some heavy metals. In this assay, heavy metals ions accumulated on the cysteine‐modified CNT electrode surfaces prior to being subjected to differential pulse anodic stripping voltammetry analysis. The resulting peak currents were linearly related to the concentrations of the metal ions. The method was optimized with respect to accumulation time, reduction time and reduction potential. The detection limits were found to be 1 ppb and 15 ppb for Pb2+ and Cu2+ respectively. The technique was used for the detection of Pb2+ and Cu2+ in spiked lake water. The average recoveries of Pb2+ and Cu2+ were 96.2% and 94.5% with relative standard deviations of 8.43% and 7.53% respectively. The potential for simultaneous detection of heavy metal ions by the modified CNTs was also demonstrated.

Department(s)

Chemistry and Biochemistry

Document Type

Article

DOI

https://doi.org/10.1002/elan.200904588

Keywords

nanotubes, heavy metals detection, stripping voltammetry, chemically modified electrodes, cysteine, trace analysis

Publication Date

2009

Journal Title

Electroanalysis

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