title: Plasmonic gold nanocrosses with multidirectional excitation and strong photothermal effect.
abstract: We report a facile chemical synthesis of well-defined gold nanocrosses through anisotropic growth along both <110> and <001>, whereas gold nanorods grow only along either <110> or <001>. The multiple branching was achieved by breaking the face-centered-cubic lattice symmetry of gold through copper-induced formation of single or double twins, and the resulting gold nanocrosses exhibited pronounced near-IR absorption with a great extension to the mid-IR region. As studied by discrete dipole approximation (DDA) simulations, the entire nanocross gets excited even when one of the branches is exposed to incident light. The above properties make them useful as octopus antennas for capturing near-IR light for effective photothermal destruction of cells. The cell damage process was analyzed using the Arrhenius model, and its intrinsic thermodynamic characteristics were determined quantitatively. Besides effective photothermal treatment and two-photon luminescence imaging, the near- and mid-IR-absorbing gold nanocrosses may also find applications in IR sensing, thermal imaging, telecommunications, and the like.
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 3 Research Link, Singapore 117602.
authors.forename: Enyi
authors.initials: E
authors.lastname: Ye
authors.forename: Khin Yin
authors.initials: KY
authors.lastname: Win
authors.forename: Hui Ru
authors.initials: HR
authors.lastname: Tan
authors.forename: Ming
authors.initials: M
authors.lastname: Lin
authors.forename: Choon Peng
authors.initials: CP
authors.lastname: Teng
authors.forename: Adnen
authors.initials: A
authors.lastname: Mlayah
authors.forename: Ming-Yong
authors.initials: MY
authors.lastname: Han
mesh_terms: D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008027:Light; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D043942:Nanotubes / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D020349:Surface Plasmon Resonance; D013696:Temperature
chemical_list: D006046:Gold