HIGH-TEMPERATURE OPERATING BIOSENSOR FOR THE DETERMINATION OF PHENOL AND RELATED-COMPOUNDS

Living phenol-oxidizing Bacillus stearothermophilus cells were immobil ized in a hydroxyethyl methacrylate membrane. A thermostable biosensor was developed by coupling the bacterially activated membrane with a d issolved oxygen electrode and was utilized for the amperometric determ ination of phenols. Linear relationships were obtained for phenol, cat echol and some related compounds. The steady-state response was very f ast (max. 2 min), faster than other analogous biosensors. Its response was stable, reproducible for months and quite specific. The biosensor may be utilized over a wide temperature (35-55 degrees C), pH (4.5-8. 0) range and in matrices containing compounds toxic for most micro-org anisms and enzymes used. The best performance was observed at 55 degre es C and pH 7.2. Owing to its sensitivity, stability and operational s implicity, the phenol biosensor can potentially be applied for the on- line monitoring of phenols in industrial waste effluents.