Application of cysteine monolayers for electrochemical determination of sub-ppb copper(II)

Citation
Ac. Liu et al., Application of cysteine monolayers for electrochemical determination of sub-ppb copper(II), ANALYT CHEM, 71(8), 1999, pp. 1549-1552
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences
Journal title
ANALYTICAL CHEMISTRY
ISSN journal
0003-2700 → ACNP
Volume
71
Issue
8
Year of publication
1999
Pages
1549 - 1552
Database
ISI
SICI code
0003-2700(19990415)71:8<1549:AOCMFE>2.0.ZU;2-U
Abstract
Electrodes with the functionality of amino acids can be easily prepared by taking advantage of strong sulfur-gold interactions and immersing gold elec trodes into cysteine solutions. Such electrodes exhibit excellent sensitivi ty and selectivity toward copper(II) determination, because the bidentate c helation of amino acids toward copper(II) is effective and far superior tha n that toward any other metal ions. In this study, we demonstrate that at a preconcentration time of 5 min the cysteine-modified electrode has a dynam ic range of 2 orders of magnitude (from 5.0 to 0.050 mu g/L) and the detect ion limit is as low as 25 ng/L (0.39 nM). This method is applied to the det ermination of copper(II) in two reference materials, SLEW-2 (river water, 1 .62 mu g/L) and CASS-3 (seawater, 0.517 mu g/L). The results agree satisfac torily with the certified values.