Electrochemical and catalytic investigation of carbon paste modified with Toluidine Blue O covalently immobilised on silica gel
Toluidine Blue O (TBO) was covalently bound on silica gel and mixed with graphite powder and paraffin oil to produce modified carbon paste electrodes. The formal potential (E°′) of the covalently bound TBO was found to be −100 mV versus Ag|AgCl (KCl sat.) at pH 7.0 and the E°′ varied less than anticipated for a 2-electron–proton type mediator with pH. The bound TBO was found to act as an efficient