Quantification of ligand packing density on gold nanoparticles using ICP-OES

Abstract

In this study, a prototypical thiolated organic ligand, 3-mercaptopropionic acid (MPA), was conjugated on gold nanoparticles (AuNPs), and packing density was measured on an ensemble-averaged basis using inductively coupled plasma optical emission spectrometry. The effects of sample preparation, including centrifugation and digestion, as well as AuNP size and concentration, on recovery were investigated. For AuNPs with diameters of 5, 10, 30, 60, and 100 nm, calculated packing density is independent of size, averaging 7.8 nm(-2) and ranging from 6.7 to 9.0 nm(-2), and is comparable to reported values for MPA and similar short-chain ligands on AuNPs. These preliminary data provide fundamental information on the advantages and limitations of ICP-based analyses of conjugated AuNP systems. Moreover, they provide necessary information for the development of more broadly applicable methods for quantifying nanoparticle-ligand conjugates of critical importance to nanomedicine applications.

Radiopaque Resorbable Inferior Vena Cava Filter Infused with Gold Nanoparticles

“…The experiments were conducted in triplicate for a single suture sample. Data were analyzed using the regression results obtained from calibration curves (R 2  ≥ 0.998) plotted between the concentrations of the standard gold solutions and absorbance of gold at 191.896, 197.742, 208.207, 211.068, 242.794, and 267.594 nm 26 .…”

Controlled metal nanostructures: Fertile ground for coordination chemists

“…However, compared to molecular complexes or clusters, the precise quantification of ligands coordinated at the surface of NPs is a major difficulty. It is generally calculated from TGA (or TGA) [191] or elemental analysis [192]. These methods avoid the tedious repetition of numerous measurements required by local analysis (e.g.…”

Kinetics of the catalytic oxidation of morin on γ-Al 2 O 3 supported gold nanoparticles and determination of gold nanoparticles surface area and sizes by quantitative ligand adsorption

“…The average surface area which each 2-MBI molecule occupies, was deduced from the packing density of 2-MBI on AuNPs quantified in this study, using the analytical equation established by Elzey et al [46]. Fig.…”

“…On the basis of this packing density, the footprint of 2-MBI on AuNPs is 0.289 nm 2 per molecule. It has been reported by Elzey et al that the ligand packing density of the organothiol 3-mercaptopropionic acid (MPA) on AuNPs is size independent for AuNPs of >5 nm in diameter [46]. This suggests that ligand adsorption can be a reliable method for quantification of the AuNPs surface areas and determination of the AuNPs sizes.…”