The underlying electrode causes the reported ‘electro-catalysis’ observed at C 60-modified glassy carbon electrodes in the case of N-(4-hydroxyphenyl)ethanamide and salbutamol

Abstract

The reported ‘electro-catalysis’ of C 60-film-modified electrodes for the electrochemical oxidation of N-(4-hydroxyphenyl)ethanamide and salbutamol has been explored at boron-doped diamond and glassy carbon electrodes. Using both C 60-film-modified boron-doped diamond and glassy carbon as underlying electrode substrates no electro-catalytic response is observed using the target analytes but rather the C 60 serves to block the electrode surface. A common experimental protocol used by researchers in this field is to electrochemically pre-treat the C 60-film-modified electrode. The response of employing this electrochemical pre-treatment at both bare glassy carbon and boron-doped diamond electrodes using the target analytes reveals that no effect on the electrochemical responses obtained at the boron-doped diamond electrode whereas a slight but significant effect occurs on glassy carbon which is attributed to the likely introduction of surface oxygenated species. Consequently the previously reported ‘electro-catalysis’ using C 60-film-modified electrode is not due to C 60 itself being catalytic, but rather that substrate activation through electrode pre-treatment is responsible for the observed ‘electro-catalysis’ likely through the introduction of surface oxygenated species. This work clearly shows that substrate activation is an important parameter which researchers studying C 60-film-modified electrodes, especially in electro-analysis needs to be considered.