Effect of natural organic matter and green microalga on carboxyl-polyethylene glycol coated CdSe/ZnS quantum dots stability and transformations under freshwater conditions

Slaveykova, Vera I.; Startchev, Konstantin

doi:10.1016/j.envpol.2009.06.017

Cited by 42 publications

(26 citation statements)

References 35 publications

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“…These findings are in agreement with Ghosh et al (2008) and Domingos et al (2009), where the stability of carbon nanotube, Al 2 O 3 , and TiO 2 NP suspensions was shown to be significantly affected by humic acid, fulvic acid, and pH. Alternatively, Slaveykova and Startchev (2009) noted that humic acid had little impact on the stability or transformation of coated quantum dots. To further complicate matters, Fabrega et al (2009) reported that the stability of Ag NP suspensions was significantly increased by humic acid presence but that these changes only impacted toxicity to bacteria at pH 9.…”

Section: Discussionsupporting

confidence: 89%

Toxicity of silver and copper to Cucurbita pepo: Differential effects of nano and bulk‐size particles

Musante

White

2010

Environmental Toxicology

231

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The phytotoxicity of bulk and nanoparticle Cu and Ag was directly compared. NP Ag reduced biomass and transpiration by 66-84% when compared with bulk Ag. The Ag ion concentration was 4.4-10-times greater in NP than bulk particle solutions. The Cu ion concentration was 1.4-4.4-times greater in bulk than NP amended solutions. Humic acid (50 mg/L) decreased the ion content of bulk Cu solution by 38-42% but increased ion Cu content of NP solutions by 1.4-2.9 times. Bulk and NP Cu were highly phytotoxic; growth and transpiration were reduced by 60-70% relative to untreated controls. NP Cu phytotoxicity was unaffected by solution type, but humic acid (50 mg/L) completely alleviated phytotoxicity caused by bulk Cu. The data demonstrate differential toxicity of Ag NP relative to bulk Ag. The finding that humic acid and solution chemistry differentially impact bulk and NP behavior highlights the importance of evaluating nanoparticles under environmentally relevant conditions.

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Section: Discussionsupporting

confidence: 89%

Toxicity of silver and copper to Cucurbita pepo: Differential effects of nano and bulk‐size particles

Musante

White

2010

Environmental Toxicology

231

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“…For example, humic acid had a negligible impact on the biomass effects noted for Au and Si nano-and bulk particles. These findings agree with that of Slaveykova and Startchev (2009), who observed that humic acid had no effect on the transformation of coated quantum dots. Alternatively, humic acid seemed to alleviate some of the phytotoxicity experienced upon exposure to bulk and NP Cu, as well as NP Ag and bulk activated carbon.…”

Section: Plant Biomass and Transpirationsupporting

confidence: 94%

Accumulation and Phytotoxicity of Engineered Nanoparticles toCucurbita Pepo

Hawthorne

Musante

Sinha

et al. 2012

International Journal of Phytoremediation

111

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The effect of bulk and engineered nanoparticle (NP) Ag, Au, Cu, Si, and C at 250 and 750 mg/L on zucchini biomass, transpiration, and element content was determined. The pH of bulk and NP solutions prior to plant growth frequently differed. Nanoparticle Cu solution pH was significantly higher than bulk Cu, whereas for Ag and C, the NPs had significantly lower pH. Plants were unaffected by Au, regardless of particle size or concentration. NP Ag reduced plant biomass and transpiration by 49-91% compared to equivalent bulk Ag. NP Si at 750 mg/L reduced plant growth and transpiration by 30-51% relative to bulk Si. Bulk and NP Cu were phytotoxic but much of the effect was alleviated by humic acid. The shoot Ag and Cu content did not differ based on particle size or concentration. The accumulation of bulk Au was greater than the NP, but humic acid increased the accumulation of NP and bulk Au by 5.6-fold and 80%, respectively. The uptake of NP Si was 5.6-6.5-fold greater than observed with the bulk element. These findings show that the NPs may have unique phytotoxicity or accumulation patterns and that solution properties can significantly impact particle fate and effects.

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“…Overall, the results shown here are in agreement with other studies of polymer-coated QDs in electrolyte supplemented with different DOM. 41,42 The particle size and the state of aggregation of the QDs were further corroborated at selected conditions using TEM. SI Figure S3 shows representative images of the CdTe and CdSe QDs suspended in 1 mM and 100 mM KCl.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Deposition Kinetics of Quantum Dots and Polystyrene Latex Nanoparticles onto Alumina: Role of Water Chemistry and Particle Coating

Quevedo

Olsson

Tufenkji

2013

Environ. Sci. Technol.

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A clear understanding of the factors controlling the deposition behavior of engineered nanoparticles (ENPs), such as quantum dots (QDs), is necessary for predicting their transport and fate in natural subsurface environments and in water filtration processes. A quartz crystal microbalance with dissipation monitoring (QCM-D) was used to study the effect of particle surface coatings and water chemistry on the deposition of commercial QDs onto Al2O3. Two carboxylated QDs (CdSe and CdTe) with different surface coatings were compared with two model nanoparticles: sulfate-functionalized (sPL) and carboxyl-modified (cPL) polystyrene latex. Deposition rates were assessed over a range of ionic strengths (IS) in simple electrolyte (KCl) and in electrolyte supplemented with two organic molecules found in natural waters; namely, humic acid and rhamnolipid. The Al2O3 collector used here is selected to be representative of oxide patches found on the surface of aquifer or filter grains. Deposition studies showed that ENP deposition rates on bare Al2O3 generally decreased with increasing salt concentration, with the exception of the polyacrylic-acid (PAA) coated CdTe QD which exhibited unique deposition behavior due to changes in the conformation of the PAA coating. QD deposition rates on bare Al2O3 were approximately 1 order of magnitude lower than those of the polystyrene latex nanoparticles, likely as a result of steric stabilization imparted by the QD surface coatings. Adsorption of humic acid or rhamnolipid on the Al2O3 surface resulted in charge reversal of the collector and subsequent reduction in the deposition rates of all ENPs. Moreover, the ratio of the two QCM-D output parameters, frequency and dissipation, revealed key structural information of the ENP-collector interface; namely, on bare Al2O3, the latex particles were rigidly attached as compared to the more loosely attached QDs. This study emphasizes the importance of considering the nature of ENP coatings as well as organic molecule adsorption onto particle and collector surfaces to avoid underestimating ENP mobility in natural and engineered aquatic environments.

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Effect of natural organic matter and green microalga on carboxyl-polyethylene glycol coated CdSe/ZnS quantum dots stability and transformations under freshwater conditions

Cited by 42 publications

References 35 publications

Toxicity of silver and copper to Cucurbita pepo: Differential effects of nano and bulk‐size particles

Toxicity of silver and copper to Cucurbita pepo: Differential effects of nano and bulk‐size particles

Accumulation and Phytotoxicity of Engineered Nanoparticles toCucurbita Pepo

Deposition Kinetics of Quantum Dots and Polystyrene Latex Nanoparticles onto Alumina: Role of Water Chemistry and Particle Coating

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