title: Determination of gold nanoparticles in environmental water samples by second-order optical scattering using dithiotreitol-functionalized CdS quantum dots after cloud point extraction.
abstract: This work presents a new method for the sensitive and selective determination of gold nanoparticles in water samples. The method combines a sample preparation and enrichment step based on cloud point extraction with a new detection motif that relies on the optical incoherent light scattering of a nano-hybrid assembly that is formed by hydrogen bond interactions between gold nanoparticles and dithiotreitol-functionalized CdS quantum dots. The experimental parameters affecting the extraction and detection of gold nanoparticles were optimized and evaluated to the analysis of gold nanoparticles of variable size and surface coating. The selectivity of the method against gold ions and other nanoparticle species was also evaluated under different conditions reminiscent to those usually found in natural water samples. The developed method was applied to the analysis of gold nanoparticles in natural waters and wastewater with satisfactory results in terms of sensitivity (detection limit at the low pmolL-1levels), recoveries (>80%) and reproducibility (<9%). Compared to other methods employing molecular spectrometry for metal nanoparticle analysis, the developed method offers improved sensitivity and it is easy-to-operate thus providing an additional tool for the monitoring and the assessment of nanoparticles toxicity and hazards in the environment.
authors.affiliation: Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
authors.forename: Spyridoula P
authors.initials: SP
authors.lastname: Mandyla
authors.affiliation: Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
authors.forename: George Z
authors.initials: GZ
authors.lastname: Tsogas
authors.affiliation: Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Vlessidis
authors.affiliation: Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece. Electronic address: dgiokas@cc.uoi.gr.
authors.forename: Dimosthenis L
authors.initials: DL
authors.lastname: Giokas
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D005591:Chemical Fractionation; D004229:Dithiothreitol / Q000737:chemistry*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005618:Fresh Water / Q000737:chemistry; D006046:Gold / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019187:Cadmium Compounds; D004229:Dithiothreitol; D006046:Gold; D013440:Sulfides; D062065:Wastewater; D014874:Water Pollutants, Chemical; C034939:cadmium sulfide
keywords: Cloud point extraction; Environmental samples; Gold nanoparticles; Second-order scattering