Studies of o-Tolidine Attachment to Pyrolytic Graphite Electrodes via Cyanuric Chloride

o-Tolidine, OT, which contains amino functional groups, was covalently attached to pyrolytic graphite electrodes via cyanuric chloride. These OT bound electrodes were examined by cyclic voltammetry and X-ray photoelectron spectroscopy, XPS. The cyclic voltammetric results for bound OT were similar to solution OT, although continual potential cycling produced changes in the XPS spectra which could be attributed to the presence and loss of some of the amine in the form of the hydrochloride salt. The bound OT was chemically stable to repeated potential scans from 0.0 to +0.8 V vs. SCE in acetonitrile solution. The surface coverages of OT from electrochemical and XPS data were estimated to be 2-5 X 10-11 mole/cm2.