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Detection of Trace Heavy Metal Ions Using Carbon Nanotube‐ Modified Electrodes
Author(s) -
Morton Jeffrey,
Havens Nathaniel,
Mugweru Amos,
Wanekaya Adam K.
Publication year - 2009
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200904588
Subject(s) - metal ions in aqueous solution , carbon nanotube , anodic stripping voltammetry , metal , detection limit , electrode , chemistry , trace amounts , voltammetry , ion , trace metal , analytical chemistry (journal) , inorganic chemistry , electrochemistry , materials science , chromatography , nanotechnology , organic chemistry , medicine , alternative medicine , pathology
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 Pb 2+ and Cu 2+ respectively. The technique was used for the detection of Pb 2+ and Cu 2+ in spiked lake water. The average recoveries of Pb 2+ and Cu 2+ 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.