Studies of a disposable biosensor based on the β-cyclodextrin inclusion complex as mediator

This paper reports the use of a disposable voltammetric biosensor based on a screen-printed basal electrode and highly efficient mediators, the beta -cyclodextrin inclusion complexes tetramethylbenzidine and ferrocene. The polyphenol oxidase, contained in the crude extract of mushroom, was immobilized in the membrane of the cross-linked beta -cyclodextrin polymer. The resulting biosensor gave excellent analytical performance due to the supramolecular complexation for mediators. It responded to the concentration of dopamine with high selectively in the range from 1.0 x 10(-9) to 1.0 x 10(-6) M with a detection limit as low as 5 x 10(-10) M. The response time for reaching 90% of its steady-state value was less than 60 s, and the activity was retained for at least 15 days. (C) 2001 Elsevier Science.