Jump to main content
Jump to site search

Issue 7, 2012
Previous Article Next Article

Effects of natural organic matter type and concentration on the aggregation of citrate-stabilized gold nanoparticles

Author affiliations

Abstract

The aggregation of 12 nm citrate-stabilized gold nanoparticles (cit-AuNPs) in the presence of four different natural organic matter (NOM) isolates and a monovalent electrolyte (KCl) was evaluated using time-resolved dynamic light scattering. All four NOM isolates stabilized the cit-AuNPs with respect to aggregation. However, specific effects varied among the different NOM isolates. At pH = 6 in 80 mM KCl, low concentrations (<0.25 mg C per L) of large molecular weight Suwannee River Humic Acid (SRHA) was required to stabilize cit-AuNPs, while larger concentrations (>2 mg C per L) of smaller Suwannee River Fulvic Acid (SRFA) were necessary at the same ionic strength. Suwannee River NOM (SRNOM) which contains both SRHA and SRFA behaved in a manner intermediate between the two. Pony Lake Fulvic Acid (PLFA), an autochthonous NOM isolate, provided substantial stability at low concentrations, yet aggregation was induced at NOM concentrations > 2 mg C per L, a trend that is hypothesized to be the result of favourable hydrophobic interactions between coated particles induced at increased surface coverage. For all NOM isolates, it appears that NOM adsorption or conformational changes at the AuNP surfaces result in significant increases in the hydrodynamic diameter that aren't attributable to NP–NP aggregation.

Graphical abstract: Effects of natural organic matter type and concentration on the aggregation of citrate-stabilized gold nanoparticles

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Jan 2012, accepted on 22 Mar 2012 and first published on 23 Mar 2012


Article type: Paper
DOI: 10.1039/C2EM00005A
J. Environ. Monit., 2012,14, 1885-1892

  •   Request permissions

    Effects of natural organic matter type and concentration on the aggregation of citrate-stabilized gold nanoparticles

    J. A. Nason, S. A. McDowell and T. W. Callahan, J. Environ. Monit., 2012, 14, 1885
    DOI: 10.1039/C2EM00005A

Search articles by author

Spotlight

Advertisements