Effect of microelectrode structure on electrocatalysis at nucleic acid-modified sensors

Yi Ge Zhou, Ying Wan, Andrew T. Sage, Mahla Poudineh, Shana O. Kelley*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


The electrochemical detection of nucleic acids using an electrocatalytic reporter system and nanostructured microelectrodes is a powerful approach to ultrasensitive biosensing. In this report we systematically study for the first time the behavior of an electrocatalytic reporter system at nucleic acid-modified electrodes with varying structures and sizes. [Ru(NH3)6]3+ is used as a primary electron acceptor that is electrostatically attracted to nucleic acid-modified electrodes, and [Fe(CN)6]3- is introduced into the redox system as a secondary electron acceptor to regenerate Ru3+ after electrochemical reduction. We found that the electrode structure has strong impact on mass transport and electron-transfer kinetics, with structures of specific dimensions yielding much higher electrochemical signals and catalytic efficiencies. The electrocatalytic signals obtained when gold sensors were electrodeposited in both circular and linear apertures were studied, and the smallest structures plated in linear apertures were found to exhibit the best performance with high current densities and turnover rates. This study provides important information for optimal assay performance and insights for the future design and fabrication of high performance biomolecular assays.

Original languageEnglish (US)
Pages (from-to)14322-14328
Number of pages7
Issue number47
StatePublished - Dec 2 2014
Externally publishedYes

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry


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