Studies on the kinetics of ascorbate oxidation at a ruthenium oxide hexacyanoferrate modified electrode towards the detection at microenvironments |
| |
Authors: | Thiago RLC Paixo Mauro Bertotti |
| |
Institution: | aInstituto de Química, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil |
| |
Abstract: | The electrocatalytic oxidation of ascorbate on a ruthenium oxide hexacyanoferrate (RuOHCF) glassy carbon (GC) modified electrode was investigated at pH 6.9 by using rotating disc electrode (RDE) voltammetry. The influence of the systematic variation of rotation rate, film thickness, ascorbate concentration and the electrode potential indicated that the rate of cross-chemical reaction between Ru(III) centres immobilized into the film and ascorbate controls the overall process. The kinetic regime may be classified as a Sk″ mechanism and the second order rate constant for the surface electrocatalytic reaction was found to be 1.56 × 10−3 mol−1 L1 s−1 cm. A carbon fibre microelectrode modified with the RuOHCF film was successfully used as an amperometric sensor to monitor the ascorbate diffusion in a simulated microenvironment experiment. |
| |
Keywords: | Ascorbate Microenvironment Ruthenium oxide hexacyanoferrate Microelectrode |
本文献已被 ScienceDirect 等数据库收录! |