Application of biotin-streptavidin technology in developing a xanthine biosensor based on a self-assembled...

We have designed an amperometric xanthine minibiosensor based on a supported biotinylated phospholipid membrane. To this membrane streptavidin-modified xanthine oxidase was coupled. The fabricated biosensor corresponds in shape and size to a needle of 0.3 mm in diameter. The assay is based on the electrochemical detection of enzymatically generated hydrogen peroxide. The response to xanthine was linear up to 1 mmol.l-1 with a detection limit of 0.02 mmol.l-1. The response time was less than one minute and the biosensor was stable for at least five days.