Development and optimization of a solid composite tyrosinase biosensor for phenol detection in flow injection systems

✍ Scribed by E. S. Mareikelutz; Elena Dominguez

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 787 KB
• Volume: 8
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.1140080204

✦ Synopsis

Bulk-modified epoxy-graphite tyrosinase biosensors were fabricated by four different procedures. The influence of these fabrication procedures on the analytical performance of the enzyme electrode in an amperometric wall-jet flow cell has been studied. The bioprobe performance is assessed by cyclic voltammetry. Higher current densities and narrower peaks were obtained when the enzyme was introduced in the dry state into the epoxy-graphite material, instead of introducing it previously dissolved in the buffer. In the F1 system responses of 11.79 pA cm-' and 1.43 pA cm-' are then obtained for catechol and phenol respectively for 50 pL injections of 20 pM solutions. Moreover, if gold/palladium is introduced into the epoxy-graphite, a further increase in current is achieved resulting in 27.70 pA cmpz and 4.90pA cmp2 for catechol and phenol, respectively. This biosensor can operate in aqueous as well as in mixed aqueous-organic environments.