Electrochemical sensor based on carbon paste electrode modified with nanostructured cryptomelane-type manganese oxides for detection of heavy metals

Xiaoli Cui, Guodong Liu, Liyu Li, Wassana Yantasee, Yuehe Lin

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

A carbon paste electrode modified with nanostructured cryptomelane-type (potassium) manganese oxides was evaluated as new electrochemical sensor for the detection of heavy metal ions in aqueous media. The cryptomelane-type manganese oxides are nanofibrous crystals with sub-nanometer tunnels which provide excellent sites for ion-exchanges. The adsorptive stripping voltammetry (ASV) technique involves preconcentration of the metal ions into nanostructured cryptomelane-type manganese oxides under an open circuit, then electrolysis of the preconcentrated species, followed by a square-wave potential sweep towards positive values. Factors affecting the preconcentration process were investigated using lead ion as the model analyte. The voltammetric responses increased with the preconcentration time from 2 to 30 min, and also linearly with lead ion concentrations ranging from 50 to 1200 ppb. The detection limits of target metal ion were 10 ppb after 4 min preconcentration and improved to 1 ppb after 20 min preconcentration. The potential for simultaneous detection of lead, silver, and copper is also discussed.

Original languageEnglish (US)
Pages (from-to)16-21
Number of pages6
JournalSensor Letters
Volume3
Issue number1
DOIs
StatePublished - Mar 1 2005

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Keywords

  • Adsorptive Stripping Voltammetry
  • Carbon Paste Electrode
  • Chemically Modified Electrode
  • Heavy Metals
  • Nanostructured Cryptomelane-Type Manganese Oxides

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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