Integrated Plasmonic Gold Nanoparticle Dimer Array for Sustainable Solar Water Disinfection.

Plasmonic nanostructures, functioning as nano-antenna reactors to highly focus light and efficiently convert it into thermal/chemical energy, have a significant potential for sustainable solar water disinfection (SODIS). A high-density plasmonic nanogap-based reactor array opens a way of maximizing the photothermal effect, but achieving uniformity and large density in such a technology while scaling up remains challenging. In this study, we provide an integrative plasmonic dimer array (hPDA) that is uniform and has high density ensuring significantly enhanced SODIS performance. The hPDA is constructed by a combined fabrication of the self-assembled monolayer and block copolymer lithography approaches. This combination leads to a two-dimensional hexagonal array of the Au dimer structures consisting of a 1.3 nm nanogap. The uniformity and high density of nanogaps of the hPDA result in the physically and optically stabilized dimer array, which allows strong light focusing and a rapid and highly efficient harvesting of photothermal energy in the visible region. Finally, the integrated hPDA with an optofluidic reactor enables 5-fold enhanced Escherichia coli (E. coli) disinfection. We anticipate that the hPDA will be useful in the scalable sustainable energy and environmental process that converts solar energy. [ABSTRACT FROM AUTHOR]