Self-assembly of silver nanoparticles into dendritic flowers from aqueous solution

Abstract

Similar to folding of proteins into three-dimensional (3D) structure, self-assembly of metallic nanoparticles (NPs) into dendritic or other supramolecular structures is of greater interest, yet less understood. We observed spontaneous, template-free organisation of silver NPs into 3D, dendritic, elegant, flower-like structures from an aqueous solution containing AgNO 3 and L-cysteine (Cys). The resultant NPs and dendritic structures were characterised using UV-Vis spectroscopy and scanning and transmission electron microscopy. The process initiated most likely by diffusion-limited aggregation in the liquid phase, which were further grown into elegant, dendritic flowers probably by evaporation of residual wetting layer of larger NPs. Electrostatic attraction between -COO À and -NH 3 þ groups of L-Cys on the surface of silver NPs may also have a role in their growth.

Growth of silver dendritic nanostructuresvia electrochemical route

“…It is also revealed that the intensity of the wide absorption band increases due to the formation of a large number of highly dense nanoparticles most likely by diffusion-limited-aggregation (DLA). 23 As reported before, 24 the wide absorption over the near infra red region of the absorption spectrum is due to red shift of relatively intense in-plane dipole resonance where the size distribution and high degree of alignment of the dendritic structure is present.…”

Chitosan/silver nanocomposites: Synergistic antibacterial action of silver nanoparticles and silver ions

“…Absorptions peaks centered between 270 and 300 nm are in place of those related to nanoparticles and can be assigned to different clusters of silver ions such as Ag + , Ag +2 , Ag +3 [33][34][35]. This means that the majority of Ag + ions chemically interact with the dilute acetic acid and form CS/silver acetate as a source of silver ions [27].…”

Gels of cysteine/Ag-based dilute colloid systems and their rheological properties

“…This reaction can be written as Such a reaction scheme was proposed in ref. 37 in the study of the creation of silver nano-particles forming fractal dendritic flowerlike structures. The authors of the cited publication used the same reagents as in this study but taken in other ratios and concentrations.…”