Abstract
A microbial biosensor for ethanol determination was prepared by immobilization of yeast cells of Saccharomyces ellipsoideus on the surface of an oxygen electrode with electrolyte in nonaqueous medium. Analytical determination is based on the respiratory activity of the microorganism in presence of the analyte. Response time of approximately 5 min for steady-state method and 2 min for kinetic method was registered. A lower detection limit of 6 μM was achieved comparing with previously reported biosensor. The major interfering compound in ethanol assay was glucose. Use of a second PTFE membrane to cover the biocatalytical yeast layer allowed developing a highly selective biosensor for ethanol.