M.V. Sangaranarayanan

The applicability of tin submicroparticles modified glassy carbon electrodes for sensing of nitrite ions is demonstrated. Tin submicroparticles have been electrodeposited on a glassy carbon electrode using constant potential deposition. The detection of nitrite ions is carried out with differential pulse voltammetry, amperometry and electrochemical impedance spectroscopy. The lowest detection limit of 0.5μM with a linear range of 5μM-1000μM is inferred from the differential pulse voltammetry. The interference from different compounds such as urea, glucose and nitrate ions is also analyzed.

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.