Voltammetric Behavior of a Chemically Modified Silsesquioxane with 4-Amino-5-Phenyl-4h-[1,2,4]-Triazole-3-Thiol and its Application for Detection of L-Dopamine

A hybrid nanocomposite formed by interaction of a octakis(3-chloropropyl) octasilsesquioxane (SS) modified with 4-Amino-5-Phenyl-4H-1,2,4-Triazole-3-Thiol (APhTT), and its subsequent reaction with copper and hexacyanoferrate (III) (CuHSA) was incorporated into a graphite paste electrode and the electrochemical studies were conducted with cyclic voltammetry. The cyclic voltammogram of the graphite paste electrode modified with CuHSA, showed one redox couple with average potential E-theta = 0.71V (vs Ag/AgCl(sat.)), attributed to the (CuFeII)-Fe-II(CN)(6)/(CuFeIII)-Fe-II(CN)(6) process (20% w/w; v= 20 mV s(-1); KCl; 1.00 mol L-1) The graphite paste electrode modified with CuHSA allowed the electrocatalytic determination of L-Dopamine using electrochemical techniques such as, cyclic voltammetry and differential pulse voltammetry. Through differential pulse voltammetry was possible to evidence two linear regions in the studied concentration range and the detection limit obtained by this technique was lower than that obtained by the technique of cyclic voltammetry.