Permselective behaviour of an electrosynthesized, non-conducting 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 non-conducting polymer of poly(2-naphthol) on a platinum electrode. Such a resulting thin film displays an interesting permselective behaviour, which proved useful in minimising the interference of ascorbate, acetaminophen, cysteine and urate sample molecules. Electrochemical detection in flowing streams was used to investigate the relevance of permselectivity for sensor development. Non-conducting poly(2-naphthol) film demonstrated useful also as a novel permselective membrane for glucose oxidase immobilization. The glucose response time, t0.95, evaluated in batch addition experiments, was lower than 4s. The calibration curve was linear up to 15 mM of glucose with a sensitivity of 2.2 nA/mM.