A potentiometric oxygen electrode was successfully used to produce a microbial biosensors with an extended response range, based on
immobilised yeast cells (Saccharomyces ellipsoideus). The response for ethanol takes ca. 7 min for the steady-state method and 2 min for
kinetic measurements. A linear calibration achieved over more than two decades of ethanol concentration. Selective determination of ethanol
in the presence of non-volatile compounds was achieved using a second PTFE membrane to cover the biocatalytic layer.