Fabrication and Characterisation of Leak-Tight Glassy Carbon Electrodes,Sealed in Glass Employing Silicon Coating,for Use in Electrochemical Detection

Abstract

Glassy carbon discs have been coated with silicon in a chemical vapour deposition process to obtain leak-tight electrodes, sealed in glass. Electrodes with coatings thicker than 5μm prove to be leak-tight in contrast with uncoated ones. Silicon-coated electrodes show faster decay of charging current, less noise and decreased background current. Leak-tightness and electron microscope information correlate well with the electrochemical data. All results can be ascribed to the absence of a void between glassy carbon and glass at Si-coated electrodes. By silicon coating, signal-to-noise ratios are improved with a factor of about 5, as is demonstrated for catecholamines and metabolites in liquid chromatography with electrochemical detection.