Comparison of nanostructured silver-modified silver and carbon ultramicroelectrodes for electrochemical detection of nitrate

Hamid R. Lotfi Zadeh Zhad, Rebecca Y. Lai

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

We report the use of silver (Ag)-modified carbon and Ag ultramicroelectrodes (UMEs) for electrochemical detection of nitrate. We investigated several methods for electrodeposition of Ag; our results show that the addition of a complexation agent (ammonium sulfate) in the Ag deposition solution is necessary for electrodeposition of nanostructured Ag that adheres well to the electrode. The electrodeposited Ag on both types of electrodes has branch-like structures that are well-suited for electrocatalytic reduction of nitrate. The use of UMEs is advantageous; the sigmoidal-shaped cyclic voltammogram allows for sensitive detection of nitrate by reducing the capacitive current, as well as enabling easy quantification of the nitrate reduction current. Both cyclic voltammetry and chronoamperometry were used to characterize the electrodes; and independent of the electrochemical interrogation technique, both UMEs were found to have a wide linear dynamic range (4-1000 μM) and a low limit of detection (3.2-5.1 μM). More importantly, they are reusable up to ~100 interrogation cycles and are selective enough to be used for direct detection of nitrate in a synthetic aquifer sample without any sample pretreatment and/or pH adjustment.

Original languageEnglish (US)
Pages (from-to)153-159
Number of pages7
JournalAnalytica Chimica Acta
Volume892
DOIs
Publication statusPublished - Sep 10 2015

    Fingerprint

Keywords

  • Carbon fiber ultramicroelectrode
  • Chronoamperometry
  • Cyclic voltammetry
  • Electrodeposited silver
  • Nitrate
  • Silver ultramicroelectrode

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Environmental Chemistry
  • Spectroscopy

Cite this