Biodirected synthesis and nanostructural characterization of anisotropic gold nanoparticles.
Gold nanoparticles with anisotropic structures have tunable absorption properties and diverse bioapplications as image contrast agents, plasmonics, and therapeutic-diagnostic materials. Amino acids with electrostatically charged side chains possess inner affinity for metal ions. Lysine (Lys) efficiently controlled the growing into star-shape nanoparticles with controlled narrow sizes (30-100 nm) and produced in high yields (85-95%). Anisotropic nanostructures showed tunable absorbance from UV to NIR range, with extraordinary colloidal stability (-26 to -42 mV) and surface-enhanced Raman scattering properties. Advanced electron microscopy characterization through ultra-high-resolution SEM, STEM, and HR-TEM confirmed the size, nanostructure, crystalline structure, and chemical composition. Molecular dynamics simulations revealed that Lys interacted preferentially with Au(I) through the -COOH group instead of their positive side chains with a binding free energy (BFE) of 3.4 kcal mol(-1). These highly monodisperse and colloidal stable anisotropic particles prepared with biocompatible compounds may be employed in biomedical applications.
Germán
G
Plascencia-Villa
Daniel
D
Torrente
Marcelo
M
Marucho
Miguel
M
José-Yacamán
D016880:Anisotropy; D003102:Colloids / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*
D003102:Colloids; D006046:Gold