title: A fluorescence quenching study of the interaction of Suwannee River fulvic acid with iron oxide nanoparticles.
abstract: The fluorescence quenching behaviour of a manufactured nanoparticle (NP, iron oxide, 7nm) on the standard Suwannee River fulvic acid (SRFA) was investigated for the first time. Size, aggregation and fluorescence was examined as a function of NP:SRFA ratio and of pH. Aggregation state varied as both a function of pH and NP:SRFA ratio, with maximum aggregation at near neutral pH values (6-8). SRFA fluorescence quenching increased non-linearly with increasing NP concentrations (>0.22x10(-3)M iron nanoparticles), indicating the complex nature of NP:SRFA interactions. Aggregates of iron oxide present at pH7-8 appeared to have a much larger effect on quenching compared with dispersed NPs or dissolved phase iron. Fluorescence quenching is demonstrated to indicate different mechanisms of NP:SRFA binding with pH.
authors.affiliation: University of Birmingham, Edgbaston, United Kingdom.
authors.forename: Adriana
authors.initials: A
authors.lastname: Manciulea
authors.forename: Andy
authors.initials: A
authors.lastname: Baker
authors.forename: Jamie R
authors.initials: JR
authors.lastname: Lead
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001578:Benzopyrans; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C005023:fulvic acid