title: Molecular linker-mediated self-assembly of gold nanoparticles: understanding and controlling the dynamics.
abstract: This study sheds light on the mechanism and dynamics of self-assembly of gold nanoparticles (AuNPs) using molecular linkers such as aminothiols. An experimental model is established that enables a fine control and prediction of both assembly rate and degree. Furthermore, we have found that under certain conditions, the increase in the molar ratio of linker/AuNPs beyond a certain threshold unexpectedly and dramatically slows down the assembly rate by charge reversal of the surface of nanoparticles. As a result, the assembly rate can be easily tuned to reach a maximum growth within seconds to several days. The decrease of the same molar ratio (linker/AuNPs) below a certain value leads to self-termination of the reaction at different phases of the assembly process, thus providing nanoparticles chains of different length. This work introduces new handles for a rational design of novel self-assembled architectures in a very time-effective manner and contributes to the understanding of the effect of the assembly morphology on the optical properties of gold nanoparticles.
authors.affiliation: Department of Mechanical Engineering and Materials Science, Washington University, St Louis, Missouri 63130, United States.
authors.forename: Abdennour
authors.initials: A
authors.lastname: Abbas
authors.forename: Ramesh
authors.initials: R
authors.lastname: Kattumenu
authors.forename: Limei
authors.initials: L
authors.lastname: Tian
authors.forename: Srikanth
authors.initials: S
authors.lastname: Singamaneni
mesh_terms: D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular
chemical_list: D006046:Gold