Electrochemical Characterization of the Microfabricated Electrochemical Sensor-Array System

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Estonian University of Life Sciences
  • University of Helsinki
  • University of Tartu

Abstract

Microfabrication technology has been used to prepare a microchip sensor-array with six sets of platinum electrodes. Chromium/platinum (10 nm/100 nm thick) were sputtered on a borosilicate wafer and patterned by wet etching method. The electrodes were designed with working electrode area of 700×400 μm in the middle and a 200 μm wide and 2600 μm long counter electrode surrounding it from three sides in a U-shape. The connection pads (1000×1500 μm) were located at the edge of a sensor-array chip. Silicon wafer was etched through to form holes with slanting side walls for immobilization cavities. The silicon and the borosilicate wafers were adhesion bonded with SU-8 epoxy resin. The cyclic voltammetry and electrochemical impedance experiments were carried out in a three-electrode electrochemical system to characterize the fabricated sensor-array chip. The results show that the current density depends on the electrode potential sweep rate ν. Also, current density depends on the concentration of potassium hexacyanoferrate(III). At slow potential sweep rates (ν≤0.01 V s−1) the steady-state signal is achieved and the electrodes behave as micro-electrodes. Such an array is a promising candidate for fast and simple biochemical oxygen demand (BOD) measurements.

Details

Original languageEnglish
Pages (from-to)249-258
Number of pages11
JournalELECTROANALYSIS
Volume29
Issue number1
Early online date17 Nov 2016
Publication statusPublished - Jan 2017
MoE publication typeA1 Journal article-refereed

ID: 9774781