M.V. Sangaranarayanan

The Potentiodynamic deposition of polyaniline on stainless steel electrodes has been carried out using the anionic surfactant sodium tetradecyl sulphate in the presence of acetic acid. The PANI-coated SS electrode was characterized using different spectroscopic and microscopic techniques. The efficacy of the electrode was analyzed for non-enzymatic sensing of D-sorbitol. Amperometric and impedimetric studies reveal the suitability of the electrode for sensing. A detection limit of 5 μM along with a linear range spanning of 75-637 μM and sensitivity of 0.027 μA μM-1 is deduced from the amperometric analysis.

The potentiodynamic polymerization of pyrrole is carried out on Pt electrodes using sodium dodecyl sulphate and the coated electrode is employed for sensing of urea non-enzymatically. Employing amperometric and impedimetric methods, urea is estimated in mildly acidic conditions. A detection limit of 40 μM is obtained along with a linearity of 80-1440 μM and a sensitivity of 1.11 μA μM-1 cm-2 from the amperometric data. The Nyquist plot is employed for the construction of the calibration curve from the impedance analysis. The interference of different compounds such as ascorbic acid, uric acid, sodium chloride and calcium chloride is also analyzed. © 2012 Elsevier B.V.