Modified working electrodes for electrochemical whole-cell microchips

Hadar Ben-Yoav, Rakefet Ofek Almog, Yelena Sverdlov, Marek Sternheim, Shimshon Belkin, Amihay Freeman, Yosi Shacham-Diamand

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


The electrode geometry and material have a significant effect on the electrochemical biochip transduction of chemical signals into electrical current or voltage. In this work we focus on the working electrode aiming to improve the signal level of live cell sensors integrated on solid-state microchips. We present here a model and measurements describing the effect of the electrode material and dimensions on the biochip performance. The research hypothesis was that the electrode transduction efficiency increases as its effective area increases. Therefore, we investigated two methods to increase the electrode effective area: 3D structures and a polymer modified electrode. An electrochemical microchip was fabricated with a working electrode that was further modified, resulting in two structure types: 3D metallic pillar-based and polypyrrole-coated. The electrochemical performance of both modified electrodes was characterized and their utilization as working electrodes in whole-cell biochips for toxicity sensing was studied. Bio-detection efficiency analysis demonstrated higher biosensing performance for the metallic (e.g. Cu/Au) pillar-based microchip than for the polypyrrole-modified and the non-modified microchips. Therefore, we conclude that the enhanced signal of the modified geometry electrode is most probably due to the increased effective surface area and the improved charge transfer efficiency.

Original languageEnglish
Pages (from-to)109-114
Number of pages6
JournalElectrochimica Acta
StatePublished - 1 Nov 2012
Externally publishedYes


  • Electrochemical biochip
  • Pillar structure
  • Polypyrrole
  • Three-dimensional electrode
  • Whole-cell biosensor

ASJC Scopus subject areas

  • General Chemical Engineering
  • Electrochemistry


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