Abstract
An amperometric principle-based biosensor containing immobilized enzyme laccase from Trametes versicolor was developed for detection of ortho-substituted phenolic derivatives. Different immobilization methods for Trametes versicolor laccase enzyme on cellophane membrane and the enhancement of operational stability of the immobilized enzyme electrode using various protein-based stabilizing agents were studied. Among tested methods of immobilization, co-cross-linking method with bovine serum albumin was superior to the other methods in terms of sensitivity, limit of detection, response time, and operating and thermal stability. Biosensor response reached steady state within 3 min and exhibited maximum activity at 45 °C and pH 6.8. The sensitivity of the ortho-substituted phenols for the test biosensor developed with co-cross-linking method of immobilization using bovine serum albumin as the protein-based stabilizing agent was in the order: 2-aminophenol > guaiacol(2-methoxyphenol) > catechol(2-hydroxyphenol) > cresol(2-methyl phenol) > 2-chlorophenol. Validation of the newly developed biosensor by comparison with HPLC showed good agreement in the results. A newly developed biosensor was applied for quantification of ortho-substituted phenols in simulated effluent samples.