Tunable Plasmon Resonance of Gold Nanoparticles Functionalized by Electroactive Bisthienylbenzene Oligomers or Polythiophene

• DOI: 10.1021/jp507210t
• Publication Date: 2014-10-06T19:16:01Z
• Authors: Delphine Schaming; Van-Quynh Nguyen; Pascal Martin; Jean-Christophe L...
• Keywords: Polythiophene

We investigate the effect of new redox molecular switches based on oligothiophene deposited gold nanoparticles (AuNPs) as thin electroactive layers in 5–80 nm thickness range. In doing so, we compare systems physisorbed (weak electronic coupling) with those covalently bonded (strong coupling), and orientation effects. Two different deposition methods were used. The first is bithiophene electropolymerization second diazonium salt electroreduction. both cases, switching layer makes possible to tune plasmonic properties AuNPs, has a strong impact amplitude localized surface plasmon resonance (LSPR) modulation. LSPR modulation upon also depends coupling regime between AuNP organic layer. Indeed, apparent real part dielectric constant seen by larger when oligothiophenes are AuNPs. Moreover, wavelength, 700–750 range, shifts opposite direction weak or interaction These behaviors may be attributed effects, but suggest that, regime, delocalization within grafted conducting material enhanced.