Construction of an amperometric polyphenol biosensor based on PVA membrane.

摘要

A method is described for construction of an amperometric biosensor for determination of polyphenolic content using polyvinyl alcohol membrane bound polyphenol oxidase mounted on a gold coated Ag wire as a working electrode, a silver/silver chloride (Ag/AgCl) reference electrode and Pt wire as auxiliary electrode. The biosensor showed optimum response within 30 s, when operated at 30 degrees C. A linear relationship was obtained between L-DOPA concentration (0.5-20 muM) and current ( muA). Limit of detection of the method was 0.5 muM. The biosensor measured polyphenols in tea leaves, alcoholic beverages and water. The enzyme electrode was used 280 times over 6 months, when stored at 4 degrees C. The biosensor is better than earlier membrane based biosensors in terms of detection limit (0.5 muM) and stability (6 months)