SEDL / STP / STP1506-EB / STP48749S

Performance of an Enzyme Electrode Designed for a Sulfide Monitoring Biosensor

Sooknah, Reeta
Natural Resources Canada, Ottawa, Ontario

Papavinasam, Sankara
Natural Resources Canada, Ottawa, Ontario

Attard, Michael
Natural Resources Canada, Ottawa, Ontario

Revie, R. Winston
Natural Resources Canada, Ottawa, Ontario

Gould, W. Douglas
Natural Resources Canada, Ottawa, Ontario

Dinardo, Orlando
Natural Resources Canada, Ottawa, Ontario

Pages: 14    Published: Jan 2009

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Abstract

The construction and evaluation of an enzyme electrode designed for a sulfide monitoring biosensor, are reported in this work. The enzyme, which is immobilized in a carbon (graphite) paste with 1,1 ′ dimeth-ylferrocene, catalyzes the oxidation of sulfide to sulfur.Amperometric measurements were carried out at room temperature, and a fixed potential of 0.3 V with reference to a saturated calomel electrode, using Tris-HCI buffer (pH 7.5) as the electrolyte, and sodium sulfide solution as the substrate. Under deaerated conditions, the biosensor responded linearly to the tested sulfide concentration range of 0–4mM, giving an average apparent Michaelis constant of 3mM, and maximum current responses between 0.7 and 3.6 uA. The sensitivity of the electrodes tested ranged from 0.2–0.3 μA mM⁻¹.