Permselective behavior of an electrosynthesized, nonconducting thin film of poly(2-naphthol) and its application to enzyme immobilization

The electrooxidation of 2-naphthol in phosphate buffer at pH 7 leads to the formation of a nonconducting polymer of poly(2-naphthol) on a platinum ele ctrode. Such a resulting thin film displays an interesting permselective be havior, which proved useful in minimizing the interference of ascorbate, ac etaminophen, cysteine, and urate sample molecules. Electrochemical detectio n in flowing streams was used to investigate the relevance of permselectivi ty for sensor development. Nonconducting poly(2-naphthol) film demonstrated useful also as a novel permselective membrane for glucose oxidase immobili zation. The glucose response time, t(0.95), evaluated in batch addition exp eriments, was lower than 4 s. The calibration plot was linear up to 15 mM o f glucose with a sensitivity of 2.2 nA/mM.