A nano-molar sensitive disposable biosensor for determination of dopamine

The studies on a nano-molar sensitive disposable biosensor based on the screen-printing basal electrode and the supramolecular assembly of dual mediators, tetramethylbenzidine and ferrocene, by beta-cyclodextrin inclusion complexation have been reported in this paper. This biosensor shows the high quality of analytical performance because of the complexation and the microenvironment in the supramolecular structure. The extracted protein of mushroom, which contains abundant polyphenol oxidase, was immobilized in the membrane of cross-linked cyclodextrin film. This biosensor responds to dopamine with high selectivity and sensitivity. Its response range on the concentration of dopamine is from 1.0 x 10(-9) to 1.0 x 10(-6) M with the detection limit as low as 5.0 x 10(-10) M. The response time reaching to 90% of its steady value is less than 60 s. The biosensor can keep its activity for at least 15 days.