Electrodes modified with an electrosynthesised Ni/Al hydrotalcite as amperometric sensors in flow systems

Pt electrodes, modified with a directly electrosynthesised film of Ni/Al-NO3 hydrotalcite were evaluated as amperometric sensors for oxidizable substrates in flow systems. The optimization of the operative parameters has been carried out using EtOH as test analyte, NaOH as carrier electrolyte and applying a constant potential. Analytical results in terms of linear range, limit of detection and precision were much satisfactory. The sensors are simple and rapid to prepare, and the coatings obtained by electrosynthesis are reproducible and stable from a mechanical point of view. The detector response was stable: a very good repeatability was observed during 12 h of flow experiments (R.S.D. < 2.6%).