Response of hydrogen peroxide, ascorbic acid, and paracetamol at a platinum electrode coated with microfilms of polyaniline

The amperometric response of hydrogen peroxide, ascorbic acid and paracetamol (which are known interferents in many enzymatic biosensors) have been studied at polyaniline (PANI) modified platinum electrodes in pH 7.0 buffer solution. Platinum electrodes covered with the films of electropolymerized PANI display reduced response both to hydrogen peroxide and paracetamol, depending on the thickness of the film. An almost 1.5 to 2.1-fold decrease in anodic current is observed both for peroxide and paracetamol in case of PANI films having a redox capacity ranging from 5 to 400 mu C cm(-2). Ascorbate, in contrast, causes an increase in current due to the electrocatalytic nature of this process. It is concluded that PANI coatings do not warrant an adequate discrimination between the analytes studied.