DIRECT COVALENT MODIFICATION OF GLASSY-CARBON SURFACES WITH 1-ALKANOLS BY ELECTROCHEMICAL OXIDATION

The modification of a glassy carbon (GC) electrode with an alkanol by electrochemical oxidation was examined. When a GC electrode was oxidiz ed by multiple potential sweep between 0 and 2.0V rs. Ag wire in 1-oct anol containing H2SO4 (1M), the electrode was modified with octanol, p robably through an ether linkage, as judged from the voltammetric beha vior of Fe(CN)(6)(3-) and catechol at the treated electrode, which clo sely resembled that at a long-chain alkanethiol-modified gold electrod e. In the modification, the potential range and the sweep rate affecte d the extent of Linking of the alcohol to the surface, and a potential sweep at 10 mV/s from 0 to 2.0V gave a GC electrode tightly covered w ith the alcohol. The membrane thus formed on the GC electrode was stab le not only to applied potential bias over the range from -0.5 to 1.5V ss. SCE (saturated calomel electrode) in 0.1 M aqueous NaCl solution but also to sonication in H2O and MeOH, n-Alkanols of various chain le ngths were also used to modify a GC electrode. The depression of the e lectrode process of Fe(CN)(6)(3-) at the modified electrodes was enhan ced as the carbon number in the modifiers increased.