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



Sherrie R. Elzey, De-Hao D. Tsai, Savelas A. Rabb, Lee L. Yu, Michael R. Winchester, Vincent A. Hackley


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 (ICP-OES). 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, σCALC, is independent of size, averaging 7.8 nm–2 and ranging from 6.7 nm–2 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.
Analytical and Bioanalytical Chemistry


functional ligand, gold nanoparticle, ICP-OES, packing density, quantitative analysis


Elzey, S. , Tsai, D. , Rabb, S. , Yu, L. , Winchester, M. and Hackley, V. (2012), Quantification of ligand packing density on gold nanoparticles using ICP-OES, Analytical and Bioanalytical Chemistry (Accessed May 24, 2024)


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Created February 18, 2012, Updated February 19, 2017