Modification of Glassy Carbon Electrode with Pyridine

摘要

Glassy carbon electrodes were modified with pyridine by electrografting of the corresponding in situ generated diazoniumcations. The diazoniumcations formation from the 3-aminopyridine in acid media at room temperature was confirmed by UV spectroscopy. The presence of immobilized pyridine at the electrode surface was demonstrated by XPS measurements. The influence of the diazotization reaction conditions on the grafting process was investigated by determination of the blocking properties of the grafted layer by electrochemical impedance spectroscopy in presence of Fe(CN)_6~(3-/4-) as redox probes. The best blocking properties of the grafted layer are obtained for a diazotization reaction of one min. and 1 equivalent of sodium nitrite.