title: Surface enhanced Raman scattering from layered assemblies of close-packed gold nanoparticles.
abstract: A synthetic method of ordering hydrophilic gold nanoparticles into a close-packed two-dimensional array at a hexane-water interface and subsequent transferring of such structure onto a solid substrate is described. By repeating the transfer process, multilayered gold nanoparticle films are formed without need of linker molecules. Their surface enhanced Raman scattering (SERS) efficiencies are compared as a function of the number of layers. It is shown that both the number of layers and the particle size contribute to SERS phenomenon. Judging from the noticeable dependence of SERS efficiency on the nanometer scale architecture, the close-packed nanoparticle formation at an immiscible interface presents a facile route to the preparation of highly active and relatively clean SERS substrates by controlling both the particle size and the film thickness. Among the investigated samples, the gold nanoparticle film assembled with quintuple layers of 30 nm diameter particles showed the maximum SERS efficiency.
authors.affiliation: Department of Chemistry and BK School of Chemical Materials Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Jung
authors.forename: Yong-Kyun
authors.initials: YK
authors.lastname: Park
authors.forename: Sungho
authors.initials: S
authors.lastname: Park
authors.forename: Seong Kyu
authors.initials: SK
authors.lastname: Kim