High-temperature operating biosensor for the determination of phenol and related compounds

Living phenol-oxidizing Bacillus stearothermophilus cells were immobilized in a hydroxyethyl methacrylate membrane. A thermostable biosensor was developed by coupling the bacterially activated membrane with a dissolved oxygen electrode and was utilized for the amperometric determination of phenols. Linear relationships were obtained for phenol, catechol and some related compounds. The steady-state response was very fast, faster than other analogous biosensors. Its response was stable, reproducible for months and quite specific. The biosensor may be utilized over a wide temperature, pH range and in matrices containing compounds toxic for most microorganisms and enzymes used. Owing to its sensitivity, stability and operational simplicity, the phenol biosensor can potentially be applied for the on-line monitoring of phenols in industrial waste effluents.