Electrochemical Sensing Platform Based on Single-Walled Carbon Nanotubes (SWCNTs)/Gold Nanoparticles (AuNps) Nanocomposite

In this paper, the electrochemical characterization and the application of a single-walled carbon nanotubes (SWCNTs)/gold nanoparticles (AuNps) nanocomposite-modified glassy carbon (GC) electrode for the preparation of electrochemical sensing platform are proposed. Inorganic electroactive compounds (i.e., probe molecules, potassium ferricyanide K3Fe(CN)(6) and hexaammine ruthenium(III) chloride [Ru(NH3)(6)]Cl-3) and molecules of biological interest such as dopamine (DA), catechol, and serotonin were employed to study their electrochemical responses at SWCNTs/AuNps/GC electrode and to compare them with those of GC bare electrode and of GC-modified electrode with SWCNTs or AuNps. The electrochemical behavior of DA, catechol, and serotonin is also investigated at two different pH values (pH 4.00 and 7.00). By comparing their electrochemical responses at SWCNTs/AuNps/GC electrode with those at conventional GC electrode, we observed different amplifications of the electrochemical signal ranging from 56% (pH 7.00) to 35% (pH 4.00) for catechol, from 73% (pH 7.00) to 35% (pH 4.00) for DA, and from 452% (pH 4.00) to 703% (pH 7.00) for serotonin; so, the nanocomposite resulted a promising material for a sensing platform.