Characterization of Submicron-Sized Carbon Electrodes Insulated with a Phenol-Allylphenol Copolymer

By careful control of the copolymerization of phenol and 2-allylphenol onto the outsides of flame-etched carbon fibers, a method to construct voltammetrtc probes with overall physical dimensions as small as 400 nm has been developed. The primary factors controlling the formation of a thin, yet Insulating, film are relative monomer concentration, polymer electrodepo-sltlon time, and electrodeposition solution pH. Optimal conditions for this procedure Involve electrodeposition for 1214 min in 60 mM phenol and 90 mM 2-ailylphenol (pH = 9.0). Success rates for construction of electrodes with total structural tip diameters below 1.5 μm Is approximately 70% and for construction of electrodes with approximately 400-nm tip diameters It Is about 10%.