The preparation of electrochemical coatings on a platmum anode, usmg phenol and dopamme solutions, are described In the amperometrrc mode, the modified electrode dlsplayed a high degree of selectlvlty to H,O, and agamst ascorbate, urate, serum and paracetamol Such selectlvlty IS supenor to that of conventional cellulose acetate membranes used m oxldase based bmsensors Most slgmfuxntly, urlth a coated electrode surface, the decrease m paracetamol response whde a large H,O, slgnal IS retamed, IS shown to alleviate the problem of paracetamol interference m a glucose sensor This glucose sensor based on glucose oxldase IS free from any slgmflcant paracetamol Interference and represents a major advance over exlstmg cellulose acetate membrane devices The Influence of both the phenohc used, and the degree of coating, on the linear response range, response time and hfetlme are discussed, and compared with a cellulose acetate membrane Keywords Amperometry, Blosensors, Glucose determmatlon, Modified electrodes, Phenols, Selectwlty Amperometrlc electrodes themselves do not dlscrlmmate between agnal and interference currents when used m conjunction Hrlth enzymes to form blosensors Durmg chmcal use, the main mterferents encountered m patrents' serum samples are ascorbate, urate, small peptldes and ammo acids, and m some cases paracetamol [l] Means must be found to ehmmate the electrode response due to these interfering species The use of the lowest polarlsmg voltage sufficient
Correspon&nce to I M Chnstle,