title: Solution-dispersible Au nanocube dimers with greatly enhanced two-photon luminescence and SERS.
abstract: We report the synthesis of 43-nm diameter Au nanocube dimers by using Ag(+) ions as competitive ligands to freeze L-cysteine-induced assembly process of the nanocubes to a desirable stage. Ascribed to the resonant interparticle coupling with an newly arising plasmon band at 710 nm and local field enhancement, the two-photon luminescence intensity of the Au nanocube dimers in solution was over 20 times stronger than that of the monomers in the wavelength range 555-620 nm. Furthermore, by coupling Raman tags onto the nanocube surface, a solution-based surface-enhanced Raman scattering (SERS) of the nanocube dimers had an enhancement factor of over 10 times compared to the isolated nanocubes. To sum up, with high stability in solution and attractive optical properties, the Au nanocube dimers have potential applications in in vivo bio-imaging and solution-based SERS.
authors: Department of Physics, School of Physics and Technology, Wuhan University, Wuhan, 430072, PR China.
authors: Xiao-Li
authors: XL
authors: Liu
authors: Shan
authors: S
authors: Liang
authors: Fan
authors: F
authors: Nan
authors: Zhong-Jian
authors: ZJ
authors: Yang
authors: Xue-Feng
authors: XF
authors: Yu
authors: Li
authors: L
authors: Zhou
authors: Zhong-Hua
authors: ZH
authors: Hao
authors: Qu-Quan
authors: QQ
authors: Wang
mesh_terms: D003545:Cysteine / Q000737:chemistry; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D007259:Infrared Rays; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D017785:Photons; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D006046:Gold; D003545:Cysteine