Star-Shaped and linear terthiophene-thiol self-assembled monolayers as scaffolds for gold nanoparticles

Self-assembled monolayers (SAMs) on gold of a new terthiophene-armed star-shaped molecule are reported. Oxidative coupling of the terthiophene (T3) ends leads to sexithiophene (T6) surface bridges. Surface plasmon spectroscopy has evidenced the ability of the T3- and T6-monolayers to coordinate gold nanoparticles. The kinetics of gold nanoparticle monolayer formation on T3- and thiol-primed surfaces has been investigated. Multilayers of oligothiophene-thiol and gold nanoparticles have been produced and compared with the analogous structures from a linear terthiophene-thiol and a generic star-shaped tetrathiol. SAMs and multilayers were characterized by CV, UV-vis, conductivity, and AFM. The conductivity of the oligothiophene-based gold multilayers is comparable with that (0.05 S cm-1) of the tetrathiol-gold multilayer.