title: Self-assembly of gibberellic amide assemblies and their applications in the growth and fabrication of ordered gold nanoparticles.
abstract: Gibberellins are a group of naturally occurring diterpenoid based phytohormones that play a vital role in plant growth and development. In this work, we have studied the self-assembly of gibberellic acid, a phytohormone, which belongs to the family of gibberellins, and designed amide derivatives of gibberellic acid (GA(3)) for the facile, green synthesis of gold nanoparticles. It was found that the derivatives self-assembled into nanofibers and nanoribbons in aqueous solutions at varying pH. Further, upon incubation with tetrachloroaurate, the self-assembled GA(3)-amide derivatives efficiently nucleated and formed gold nanoparticles when heated to 60 degrees C. Energy dispersive x-ray spectroscopy, transmission electron microscopy and scanning electron microscopy analyses revealed that uniform coatings of gold nanoparticles in the 10-20 nm range were obtained at low pH on the nanowire surfaces without the assistance of additional reducing agents. This simple method for the development of morphology controlled gold nanoparticles using a plant hormone derivative opens doors for a new class of plant biomaterials which can efficiently yield gold nanoparticles in an environmentally friendly manner. The gold encrusted nanowires formed using biomimetic methods may lead on to the formation of conductive nanowires, which may be useful for a wide range of applications such as in optoelectronics and sensors. Further, the spontaneous formation of highly organized nanostructures obtained from plant phytohormone derivatives such as gibberellic acid is of particular interest as it might help in further understanding the supramolecular assembly mechanism of more highly organized biological structures.
authors: Department of Chemistry, Fordham University, Bronx, NY 10458, USA.
authors: Evan M
authors: EM
authors: Smoak
authors: Andrew D
authors: AD
authors: Carlo
authors: Catherine C
authors: CC
authors: Fowles
authors: Ipsita A
authors: IA
authors: Banerjee
mesh_terms: D000577:Amides / Q000737:chemistry; D003460:Crystallization / Q000379:methods*; D005875:Gibberellins / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000577:Amides; D005875:Gibberellins; D046911:Macromolecular Substances; D010936:Plant Extracts; D006046:Gold; C007842:gibberellic acid