End-to-End Assembly of CTAB-Stabilized Gold Nanorods by Citrate Anions

We report studies on the end-to-end assembly of CTAB-stabilized gold nanorods (GNRs) dispersing in an aqueous solution. The addition of sodium citrate to the solution of GNRs with an aspect ratio (AR) of 3 causes the end-to-end assembly accompanied with a red-shift of longitudinal surface plasmon resonance (LSPR) band of the GNRs in the optical extinction spectrum. The red-shift in the LSPR band continues until the solution becomes colorless and transparent, whereas adding CTAB brings the color change to a stop, resulting in the long term-stable LSPR of the end-to-end connected GNRs. Added citrate anions are found to be adsorbed on only the end faces of GNRs so that they are considered to neutralize the surface charge of the GNR ends, resulting in the end-to-end assembly of the GNRs. On the other hand, GNRs with an AR of 16 are end-to-end assembled by decreasing CTAB concentration in the solution. The assembled GNRs are welded at their connecting points by the further decrease of CTAB concentration in the...

[1]  M. Nogami,et al.  Facile assembling of gold nanorods with large aspect ratio and their surface-enhanced Raman scattering properties , 2007 .

[2]  Masayuki Nogami,et al.  Solvothermal Synthesis of Multiple Shapes of Silver Nanoparticles and Their SERS Properties , 2007 .

[3]  N. Nakashima,et al.  End-to-end Assemblies of Gold Nanorods Adsorbed on a Glass Substrate Modified with Polyanion Polymers , 2006 .

[4]  Masayuki Nogami,et al.  One-dimensional self-assembly of gold nanoparticles for tunable surface plasmon resonance properties , 2006 .

[5]  K. G. Thomas,et al.  Gold Nanorods to Nanochains: Mechanistic Investigations on Their Longitudinal Assembly Using α,ω-Alkanedithiols and Interplasmon Coupling , 2006 .

[6]  M. Pileni,et al.  Optical properties of gold nanorods: DDA simulations supported by experiments. , 2005, The journal of physical chemistry. B.

[7]  Anand Gole,et al.  Surface-enhanced Raman spectroscopy of self-assembled monolayers: sandwich architecture and nanoparticle shape dependence. , 2005, Analytical chemistry.

[8]  C. Murphy,et al.  Self-assembly patterns formed upon solvent evaporation of aqueous cetyltrimethylammonium bromide-coated gold nanoparticles of various shapes. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[9]  Wang Yongchang,et al.  Fluorescence spectrum properties of gold nanochains , 2004 .

[10]  Catherine J. Murphy,et al.  Seed-Mediated Synthesis of Gold Nanorods: Role of the Size and Nature of the Seed , 2004 .

[11]  Paul Mulvaney,et al.  Electric‐Field‐Directed Growth of Gold Nanorods in Aqueous Surfactant Solutions , 2004 .

[12]  Prashant V. Kamat,et al.  Uniaxial Plasmon Coupling through Longitudinal Self-Assembly of Gold Nanorods , 2004 .

[13]  Q. Jiang,et al.  Modelling of surface energies of elemental crystals , 2004 .

[14]  Uwe H F Bunz,et al.  Preferential end-to-end assembly of gold nanorods by biotin-streptavidin connectors. , 2003, Journal of the American Chemical Society.

[15]  C. Murphy,et al.  Dependence of the Gold Nanorod Aspect Ratio on the Nature of the Directing Surfactant in Aqueous Solution , 2003 .

[16]  Younan Xia,et al.  Polyol Synthesis of Uniform Silver Nanowires: A Plausible Growth Mechanism and the Supporting Evidence , 2003 .

[17]  Mostafa A. El-Sayed,et al.  Preparation and Growth Mechanism of Gold Nanorods (NRs) Using Seed-Mediated Growth Method , 2003 .

[18]  B. Nikoobakht,et al.  種結晶を媒介とした成長法を用いた金ナノロッド(NR)の調製と成長メカニズム , 2003 .

[19]  Mostafa A. El-Sayed,et al.  Surface-enhanced Raman scattering of molecules adsorbed on gold nanorods: off-surface plasmon resonance condition , 2002 .

[20]  Colby A. Foss,et al.  The Effect of Mutual Orientation on the Spectra of Metal Nanoparticle Rod−Rod and Rod−Sphere Pairs , 2002 .

[21]  M. Harmer,et al.  Surface atomic defect structures and growth of gold nanorods , 2002 .

[22]  C. J. Johnson,et al.  Growth and form of gold nanorods prepared by seed-mediated, surfactant-directed synthesis , 2002 .

[23]  Catherine J. Murphy,et al.  Wet Chemical Synthesis of High Aspect Ratio Cylindrical Gold Nanorods , 2001 .

[24]  Peidong Yang,et al.  Synthesis and assembly of BaWO4 nanorods , 2001 .

[25]  Mostafa A. El-Sayed,et al.  Self-Assembly of Gold Nanorods , 2000 .

[26]  M. El-Sayed,et al.  The `lightning' gold nanorods: fluorescence enhancement of over a million compared to the gold metal , 2000 .

[27]  J. Gabriel,et al.  New Trends in Colloidal Liquid Crystals Based on Mineral Moieties , 2000 .

[28]  Zhong Lin Wang,et al.  Crystallographic facets and shapes of gold nanorods of different aspect ratios , 1999 .

[29]  D. Frenkel,et al.  Thermodynamic stability of a smectic phase in a system of hard rods , 1988, Nature.