Abstract: In this work isopropanol(iP) oxidation was adopted as a model reaction for studying the catalytic activity of poly2,5dimethylaniline (PDMAn) and polyotoluidine (POT) membrane modified electrode. Each voltammetric curve of PDMAn and POT modified electrodes has two pair of redox peaks. In comparison with platinized Pt electrode, platinized PDMAn and POT modified electrodes enhance iP oxidation current significantly, furthermore the oxidation current increase with potential cycling numbers, whereas the oxidation current at platinized Pt electrode decreases with potential cycling numbers. It is indicated that the functional membrane modified electrode exhibits higher catalytic activity to iP oxidation. POT modified electrode with low platinum loading shows great catalytic activity for iP oxidation, and has higher response sensitivity than PDMAn in the condition of low concentration iP. It is also found that PDMAn has degraded after preservation in air for three years, while POT has excellent environmental stability. Therefore, POT is promising to be an electrochemical sensor material with practical application prospect.

Key words: Poly2,5dimethoxyaniline, Poly-o-toluidine, Stability, Polymer modified electrode, Isopropanol oxidation