Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes

Yantasee, W; Charnhattakorn, B; Fryxell, GE; Lin, YH; Timchalk, C; Addleman, RS

HERO ID

537709

Reference Type

Journal Article

Year

2008

Language

English

PMID

18558124

HERO ID 537709
In Press No
Year 2008
Title Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes
Authors Yantasee, W; Charnhattakorn, B; Fryxell, GE; Lin, YH; Timchalk, C; Addleman, RS
Journal Analytica Chimica Acta
Volume 620
Issue 1-2
Page Numbers 55-63
Abstract Electrochemical sensors have great potential for environmental monitoring of toxic metal ions in waters due to their portability; field-deployability and excellent detection limits. However, electrochemical sensors employing mercury-free approaches typically suffer from binding competition for metal ions and fouling by organic substances and surfactants in natural waters, making sample pretreatments such as wet ashing necessary. In this work, we have developed mercury-free sensors by coating a composite of thiol self-assembled monolayers on mesoporous supports (SH-SAMMS (TM)) and Nafion on glassy-carbon electrodes. With the combined benefit of SH-SAMMS (TM) as an outstanding metal preconcentrator and Nafion as an antifouling binder, the sensors could detect 0.5 ppb of Pb and 2.5 ppb of Cd in river water, Hanford groundwater, and seawater with a minimal amount of preconcentration time (few minutes) and without any sample pretreatment. The sensor could also detect 2.5 ppb of Cd, Pb, and Cu simultaneously. The electrodes have long service times and excellent single and inter-electrode reproducibility (5% R.S.D. after 8 consecutive measurements). Unlike SAMMS (TM)-carbon paste electrodes, the SAMMS (TM)-Nafion electrodes were not fouled in samples containing albumin and successfully detected Cd in human urine. Other potentially confounding factors affecting metal detection at SAMMS (TM)-Nafion electrodes were studied, including pH effect, transport resistance of metal ions, and detection interference. With the ability to reliably detect low metal concentration ranges without sample pretreatment and fouling, SAMMS (TM)-Nafion composite sensors have the potential to become the next-generation metal analyzers for environmental and bio-monitoring of toxic metals. (c) 2008 Elsevier B.V. All rights reserved.
Doi 10.1016/j.aca.2008.05.029
Pmid 18558124
Wosid WOS:000257553200007
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword electrochemical sensor; self-assembled monolayers on mesoporous; supports; Nafion; thiol; Cd; Pb; Cu; urine; natural water; anodic-stripping voltammetry; self-assembled monolayers; carbon-paste; electrode; silver electrode; heavy-metals; nanomolar concentrations; actinide sequestration; lead pb; supports; system
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