Adsorption and electropolymerization of toluidine blue on the nanostructured octakis(hydridodimethylsiloxy)octasilsesquioxane surface

Toluidine blue O (TBO) was adsorbed on the octakis(hydridodimethylsiloxy)octasilsesquioxane (Q{sub 8}M{sub 8}{sup H}) surface. The characterization of the precursor (Q{sub 8}M{sub 8}{sup H}) and resulting materials obtained by the reaction of Q{sub 8}M{sub 8}{sup H} and toluidine blue (CTBO) were defined using Fourier transform infrared spectra, nuclear magnetic resonance solid-state {sup 13}C and Si{sup 29} magic angle spinning. The electrochemical polymerization in a glassy carbon electrode was verified by means of a film silsesquioxane formation (FCTBO) using cyclic voltammetry in a potential range of -0.5 to 1.3 V (vs. saturated calomel electrode (SCE)) in a Britton Robinson (B-R) buffer solution (pH 2.0). The cyclic voltammogram of the film exhibits two redox couples with a formal potential of -0.15 and -0.02 V (B-R buffer pH 5). The formal potential shifts linearly in the cathodic direction by increasing the pH solution with a slope of 71 and 57 mV per unit for the first and second couple, respectively. The film was electrochemically very stable.