nanocomposite, biosensor, polypyrrole, sulfite, amperometry
This paper will present the results of a layer by layer strategy that we have developed for the fabrication of a polypyrrole nanocomposite amperometric biosensor for sulfite. The use of this strategy to fabricate bilayer and trilayer sulfite biosensors, consisting of nanolayers of polypyrrole-sulfite oxidase, polypyrrole-dextran-sulfite oxidase, polypyrrole-chloride and/or polypyrrole-nitrate films will be discussed. In particular, the influence of the outer nanolayer on the selective and sensitivity of the amperometric nanocomposite biosensor will be highlighted. The performance of sulfite nanocomposite biosensor in the presence and absence of interferants, such as oxalic and tartaric acids will also be discussed. Furthermore, the successful application of the nanolayer biosensor to sulfite determination in some wine and beer samples without sample pre-treatment will be demonstrated.