Fabrication of an inverse opal structure of a hybrid metal-conducting polymer for plasmon-induced hyperthermia applications.

This paper describes the effective fabrication of an inverse opal (IO) structure for plasmon-induced hyperthermia applications using silver nanoparticles (AgNPs) doped in a conducting polymer of poly(3,4-ethylene dioxythiophene) (PEDOT). Indium tin oxide (ITO) substrates were firstly modified electrochemically by a layer of the inverse opal structure of PEDOT (IO-PEDOT). These as-prepared electrodes were subsequently used as working electrodes for electrodepositing AgNPs. The presence of plasmonic AgNPs doped inside a polymer network caused the hybrid of IO-PEDOT and AgNPs to generate significantly more heat than thin-film PEDOT, thin-film PEDOT/AgNPs, and IO-PEDOT under 532 nm laser irradiation. This is attributed to the synergistic effect of the large active area inverse opal structure and doped AgNPs, which exhibit more thermal energy and heat faster than the individual component structures. These findings point to a wide range of potential applications for hybrid IO-PEDOT/AgNPs in hyperthermia treatment.

Confinement Effect of Plasmon for the Fabrication of Interconnected AuNPs through the Reduction of Diazonium Salts.

This paper describes a rapid bottom-up approach to selectively functionalize gold nanoparticles (AuNPs) on an indium tin oxide (ITO) substrate using the plasmon confinement effect. The plasmonic substrates based on a AuNP-free surfactant were fabricated by electrochemical deposition. Using this bottom-up technique, many sub-30 nm spatial gaps between the deposited AuNPs were randomly generated on the ITO substrate, which is difficult to obtain with a top-down approach (i.e., E-beam lithography) due to its fabrication limits. The 4-Aminodiphenyl (ADP) molecules were grafted directly onto the AuNPs through a plasmon-induced reduction of the 4-Aminodiphenyl diazonium salts (ADPD). The ADP organic layer preferentially grew in the narrow gaps between the many adjacent AuNPs to create interconnected AuNPs. This novel strategy opens up an efficient technique for the localized surface modification at the nanoscale over a macroscopic area, which is anticipated to be an advanced nanofabrication technique.