One step synthesis of single walled carbon nanotubes/gold nanoparticles (SWCNTs/AuNps) nanocomposite for enhancing electrochemical response of neurotransmitters

The paper reports a simple one-step procedure to synthesize Single Walled Carbon Nanotubes (SWCNTs) decorated with gold nanoparticles (AuNps). The method involves the reaction between HAuCl(4) aqueous solution and sodium citrate, used as reducing-dispersing agent, in an aqueous dispersion of SWCNTs. An accurate purification of commercial SWCNTs has been achieved, before use, according to the literature methods. Using sodium citrate as reducing agent, 10 nm in size gold nanoparticles can be obtained and an interaction between SWCNTs and AuNps could be observed by UV-Vis measurements. Gold nanoparticles size and nanocomposite morphology have been studied by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) observations. SWCNTs/AuNps nanocomposite has been used to modify conventional Glassy Carbon electrode (GCE), by dip coating technique. The SWCNTs-AuNps modified electrode was used for an electrochemical study of neurotransmitters, such as dopamine and catechol by cyclic voltammetry.