Determination of Water Content in Aprotic Solvent by Anthraquinone-Modified Multi-walled Carbon nanotubes.
The Attachment of etylenediamine bearing BOC (tert-butyloxycarbonyl) by electrochemical oxidation of corresponding diamine linker was achieved onto multi-walled carbon nanotube immobilized at glassy carbon surfaces. Subsequent to removal of BOC protecting group, the coupling of anthraquinone-2-carboxylic acid to amine-terminated surfaces was carried out using solid-phase synthesis methodology. It was demonstrated that anthraquinone exhibits electrochemically two sequential single-electron reductions in aprotic solutions through cyclic voltammetry technique. Peak separation potential between first and second electron transfer step was found to be decreased with the addition of water as a proton source. When the water concentration reaches up to 1 M, only one electrochemical process due to formation of hydrogen bonding between reduced form of anthraquinone and aprotic solvent (acetonitrile). Determination of water content in the aprotic solutions was shown to be quite possible using linear relationship between water concentration and peak separation potential. Limit of detection was also calculated to be around 1.1x10-7 M.
Carbon Nanotubes, Anthraquinone, Electrode modification, Aprotic Solvent, Water
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