Isotopically Labeled Nanoparticles at Relevant Concentrations: How Low Can We Go? The Case of CdSe/ZnS QDs in Surface Waters

Supiandi, N. Izyan; Charron, Gaëlle; Tharaud, Mickaël; Cordier, Laure; Guigner, Jean‐Michel; Benedetti, Marc F.; Sivry, Yann

doi:10.1021/acs.est.8b04096

Cited by 26 publications

(19 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2, using the DPBS matrix and based on the 111 Cd tracer. As discussed in a previous study 31 , the recovery rate of the analytical methods (i.e. the fraction of QDs detected among the QDs present in the sample), is obtained from the slope of the best linear regression model.…”

Section: Resultsmentioning

confidence: 99%

Tracing multi-isotopically labelled CdSe/ZnS quantum dots in biological media

Supiandi

Charron

Tharaud

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

the strengths and limits of isotopically labelled engineered nanoparticles (spiked enps) spread in biological media have been assessed. Multi-spiked CdSe/ZnS quantum dots (QDs), measuring 7 nm and coated with thioglycolic acid (tGA), were synthesized and enriched in 68 Zn, 77 Se and 111 cd. these QDs were dispersed at very low concentrations (0.1 to 5000 ppt) in diverse biological matrices (synthetic saliva, synthetic urine, plasma and Dulbecco's phosphate buffered saline -DPBS growth medium) and the isotopic compositions were determined by HR-icp-MS. the initial QDs concentrations were calculated to assess the limit of quantification (QD-LOQ) according to the matrix and the isotopically enriched element. the obtained results demonstrated the advantages of the isotopic labelling method in order to work at very low concentrations: the QD-LOQ values for the spiked Zn, Cd and Se originated from the QDs were 10, 0.3 and 6 ppt, respectively, which is below the conventional LOQ of the HR-ICP-MS used (30, 3 and 60 ppt for Zn, Cd and Se, respectively). Conversely, in complex matrices such as saliva, urine, plasma and DPBS growth medium, the QD-LOQ values increased significantly, with values ranging from 16 to 32 ppt for Cd, 446 to 10598 ppt for Zn and 1618 to 8317 ppt for Se. These QD-LOQs are dependent on factors as the elemental background concentration already present in the matrices, and the dilution factor. In this study, the QD-LOQs are expressed for the first time with respect to the background concentration in biological media (QD-RLOQ), which can be used to better assess and then predict the efficiency of the spiking method.

show abstract

Section: Resultsmentioning

confidence: 99%

Tracing multi-isotopically labelled CdSe/ZnS quantum dots in biological media

Supiandi

Charron

Tharaud

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CdSe/ZnS QDs used in this study were enriched in 111 Cd, 77 Se, and 68 Zn. The chemicals used including the synthesis protocol and the characterization methods of the multi-spiked QDs were described in previous works (Supiandi et al, 2019(Supiandi et al, , 2020. Briefly, a stock solution of the QDs in an organic phase was synthesized and used to prepare water-soluble QDs, i.e., functionalized with thioglycolic acid (TGA).…”

Section: Methodsmentioning

confidence: 99%

“…Batch experiments were performed, using mixtures of QDs and water with different chemical compositions and analogs of suspended matter to follow, as a function of time, the changes in chemical composition of the model surface waters. The use of isotopically modified (or "spiked") ENPs (Supiandi et al, 2019(Supiandi et al, , 2020 with centrifugal ultrafiltration (CU) separation and detection by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) overcame the analytical barriers (detection limits and geochemical background) to obtain the metal ion concentration and origins in the dissolved fraction. The speciation of QDs constituting metal ions (Cd and Zn) in the experimental systems (Domingos et al, 2008) was followed by scanned stripping chronopotentiometry (SSCP).…”

Section: Introductionmentioning

confidence: 99%

Geochemistry of Engineered Nanoparticles (CdSe/ZnS Quantum Dots) in Surface Waters

Supiandi

Domingos

Benedetti

et al. 2020

Front. Environ. Sci.

View full text Add to dashboard Cite

The difficulties when studying the behavior of engineered nanoparticles (ENPs), and the subsequent metal speciation in aquatic ecosystems, at environmentally relevant concentrations (i.e., ppt level) are often related to the occurrence of ENP constitutive elements at high concentrations as a background in aquatic media. In this study, the physicochemical behavior of CdSe/ZnS quantum dots (QDs) when spread at very low concentrations in surface waters was investigated. The above-mentioned issues were overcome with the use of isotopically labeled QDs, separated by centrifugal ultrafiltration (CU) and measured by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), combined with the detection of free and labile metal ions by scanned stripping chronopotentiometry (SSCP). They firmly provided a thorough comprehension regarding the transformation of QDs in surface waters. The physicochemical conditions of the medium including the presence of an analog of natural organic matter and a mineral (i.e., fulvic acid and goethite), the manufactured coating of the QDs [here thioglycolic acid (TGA)], and the occurrence of added Zn in the medium were considered in the study. The overall results show that, in the absence of mineral/organic matter, the TGA ligands in solution that detached from the QD surface after dissolution control the metal speciation, especially for Cd. Conversely, in a more representative aquatic ecosystem condition (i.e., with Zn in the background media together with fulvic acid and goethite), almost no Zn or Cd dissolution from the QDs is detected. SSCP measurements reveal that the Zn complexes formed with the organic/mineral material in the system are inert, whereas the speciation model calculations indicated that Cd 2+ is bound to TGA ligands in solution and organic/inorganic matter-therefore suggesting that, under the studied conditions, aquatic organisms will be exposed to a very low concentration of free and labile metal ions issued from the QDs.

show abstract

“…1 for a schematic representation of the QD). To allow their transfer to aqueous solution, they were functionalized with a layer of thioglycolic acid (TGA) ligand, following a protocol previously established by Supiandi et al (2019). To isolate and purify QDs from the reaction medium, several cycles of concentration-dispersion steps in borate buffer and milli-Q water were performed.…”

Section: Quantum Dotsmentioning

confidence: 99%

How microbial biofilms impact the interactions of Quantum Dots with mineral surfaces?

et al. 2020

View full text Add to dashboard Cite

The increasing use of Quantum Dots (QDs) -nanoparticles exhibiting unique optical propertiesand their incorporation in multiple engineering products is likely to result in the release of this new class of contaminants into natural systems. In soils, bacterial biofilms and mineral surfaces form highly reactive interfaces, which may control QDs' environmental fate. However, little is known regarding QDs' stability in, and modes of interactions with, biofilm/mineral interfaces. This study examines the interactions, distributions and stability of thioglycolic acid-capped CdSe/ZnS QDs at the corundum (-Al 2 O 3 )/Shewanella oneidensis MR-1 interface, for exposure times ranging between 1h to 24h. Long Period -X-ray Standing Wave -Fluorescence Yield spectroscopy and Grazing Incidence -X-ray Absorption Spectroscopy were used. Results indicate increases in Zn and Se concentrations within the biofilm/crystal system with time, demonstrating its high accumulation capacity over 24h. In addition, dissolution of a part of the ZnS shell occurs within 1h, highlighting the potential degradation of QDs when exposed to the biofilm/crystal compartment. Once released, Zn(II) migrates toward the biofilm-crystal interface and interacts preferentially with the crystal surface. In contrast, the remaining CdSe core is mostly preserved, and stays within the biofilm thickness. However, at 24h, Se and Zn present similar distribution profiles indicating a general reduction in ZnS shell dissolution at this longer exposure time.

show abstract

Isotopically Labeled Nanoparticles at Relevant Concentrations: How Low Can We Go? The Case of CdSe/ZnS QDs in Surface Waters

Cited by 26 publications

References 53 publications

Tracing multi-isotopically labelled CdSe/ZnS quantum dots in biological media

Tracing multi-isotopically labelled CdSe/ZnS quantum dots in biological media

Geochemistry of Engineered Nanoparticles (CdSe/ZnS Quantum Dots) in Surface Waters

How microbial biofilms impact the interactions of Quantum Dots with mineral surfaces?

Contact Info

Product

Resources

About