Fate of silver nanoparticles in natural waters; integrative use of conventional and electrochemical analytical techniques

RSC Advances ◽  
2014 ◽  
Vol 4 (10) ◽  
pp. 5006 ◽  
Author(s):  
Wei Zhe Teo ◽  
Martin Pumera
Keyword(s):  
Silver Nanoparticles ◽  
Natural Waters ◽  
Analytical Techniques

scholarly journals Heteroagglomeration of nanosilver with colloidal SiO2 and clay

2017 ◽  
Vol 14 (1) ◽  
pp. 1 ◽  
Author(s):  
Sébastien Maillette ◽  
Caroline Peyrot ◽  
Tapas Purkait ◽  
Muhammad Iqbal ◽  
Jonathan G. C. Veinot ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Polyacrylic Acid ◽  
Natural Waters ◽  
Colloidal Particles ◽  
Colloidal Stability ◽  
Analytical Techniques ◽  
Dark Field ◽  
Correlation Spectroscopy ◽  
Colloidal Clay ◽  
High Concentrations

Environmental contextThe fate of nanomaterials in the environment is related to their colloidal stability. Although numerous studies have examined their homoagglomeration, their low concentration and the presence of high concentrations of natural particles implies that heteroagglomeration rather than homoagglomeration is likely to occur under natural conditions. In this paper, two state-of-the art analytical techniques were used to identify the conditions under which nanosilver was most likely to form heteroagglomerates in natural waters. AbstractThe environmental risk of nanomaterials will depend on their persistence, mobility, toxicity and bioaccumulation. Each of these parameters is related to their fate (especially dissolution, agglomeration). The goal of this paper was to understand the heteroagglomeration of silver nanoparticles in natural waters. Two small silver nanoparticles (nAg, ~3nm; polyacrylic acid- and citrate-stabilised) were covalently labelled with a fluorescent dye and then mixed with colloidal silicon oxides (SiO2, ~18.5nm) or clays (~550nm SWy-2 montmorillonite). Homo- and heteroagglomeration of the nAg were first studied in controlled synthetic waters that were representative of natural fresh waters (50μg Ag L–1; pH 7.0; ionic strength 10–7 to 10–1 M Ca) by following the sizes of the nAg by fluorescence correlation spectroscopy. The polyacrylic acid-coated nanosilver was extremely stable under all conditions, including in the presence of other colloids and at high ionic strengths. However, the citrate-coated nanosilver formed heteroaggregates in presence of both colloidal SiO2 and clay particles. Nanoparticle surface properties appeared to play a key role in controlling the physicochemical stability of the nAg. For example, the polyacrylic acid stabilized nAg-remained extremely stable in the water column, even under conditions for which surrounding colloidal particles were agglomerating. Finally, enhanced dark-field microscopy was then used to further characterise the heteroagglomeration of a citrate-coated nAg with suspensions of colloidal clay, colloidal SiO2 or natural (river) water.

The persistence and transformation of silver nanoparticles in littoral lake mesocosms monitored using various analytical techniques

2014 ◽  
Vol 11 (4) ◽  
pp. 419 ◽  
Author(s):  
Lindsay M. Furtado ◽  
Md Ehsanul Hoque ◽  
Denise M. Mitrano ◽  
James F. Ranville ◽  
Beth Cheever ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Surface Waters ◽  
Lake Water ◽  
Natural Waters ◽  
Municipal Wastewater ◽  
Analytical Techniques ◽  
Aquatic Organisms ◽  
Silver Ions ◽  
Icp Ms ◽  
The Individual

Environmental context Silver nanoparticles discharged with municipal wastewater may contaminate surface waters and harm aquatic ecosystems. We applied several analytical techniques to investigate the persistence and transformation of silver nanoparticles in a natural lake environment, and show, through multiple lines of evidence, that they persisted in lake water for several weeks after addition. The nanoparticles were releasing silver ions through dissolution, but these toxic ions were likely binding with natural organic matter in the lake water. Abstract Silver nanoparticles (AgNPs) may be released into surface waters, where they can affect aquatic organisms. However, agglomeration, dissolution, surface modifications and chemical speciation are important processes that control the toxicity of AgNPs. The purpose of the study was to apply various methods for monitoring the persistence and transformation of AgNPs added to littoral lake mesocosms. Analysis of total Ag showed that the levels in the mesocosms declined rapidly in the first 12h after addition, followed by a slower rate of dissipation with a half-life (t1/2) of ~20 days. Analysis using single particle ICP-MS (spICP-MS) showed no evidence of extensive homo-agglomeration of AgNPs. The stability of AgNPs was likely due to the low ionic strength and high concentrations of humic-rich dissolved organic carbon (DOC) in the lake water. Analyses by spICP-MS, cloud point extraction (CPE) and asymmetric flow field flow fractionation coupled to ICP-MS (AF4-ICP-MS) all indicated that the concentrations of AgNP decreased over time, and the nanoparticles underwent dissolution. However, the concentrations of dissolved silver, which includes Ag+, were generally below detection limits when analysed by centrifugal ultrafiltration and spICP-MS. It is likely that the majority of free ions released by dissolution were complexing with natural organic material, such as DOC. An association with DOC would be expected to reduce the toxicity of Ag+ in natural waters. Overall, we were able to characterise AgNP transformations in natural waters at toxicologically relevant concentrations through the use of multiple analytical techniques that compensate for the limitations of the individual methods.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

2021 ◽  
Vol 36 (2) ◽  
pp. 93-110
Author(s):  
Princy Philip ◽  
Tomlal Jose ◽  
Sarath KS ◽  
Sunny Kuriakose
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Antibacterial Properties ◽  
Analytical Techniques ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Poly Methyl Methacrylate ◽  
Antimicrobial Studies ◽  
Eye Problems

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

scholarly journals Exposure Media and Nanoparticle Size Influence on the Fate, Bioaccumulation, and Toxicity of Silver Nanoparticles to Higher Plant Salvinia minima

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2305
Author(s):  
Melusi Thwala ◽  
Stephen Klaine ◽  
Ndeke Musee
Keyword(s):  
Silver Nanoparticles ◽  
Analytical Techniques ◽  
Hard Water ◽  
Higher Plant ◽  
X Ray ◽  
Chlorophyll Pigments ◽  
Size Dependent ◽  
Predicted Environmental Concentrations ◽  
Low Exposure ◽  
Toxicity Pattern

Silver nanoparticles (AgNPs) are favoured antibacterial agents in nano-enabled products and can be released into water resources where they potentially elicit adverse effects. Herein, interactions of 10 and 40 nm AgNPs (10-AgNPs and 40-AgNPs) with aquatic higher plant Salvinia minima at 600 µg/L in moderately hard water (MHW), MHW of raised calcium (Ca2+), and MHW containing natural organic matter (NOM) were examined. The exposure media variants altered the AgNPs’ surface properties, causing size-dependent agglomeration. The bio-accessibility in the ascending order was: NOM < MHW < Ca2+, was higher in plants exposed to 10-AgNPs, and across all exposures, accumulation was higher in roots compared to fronds. The AgNPs reduced plant growth and the production of chlorophyll pigments a and b; the toxic effects were influenced by exposure media chemistry, and the smaller 10-AgNPs were commonly the most toxic relative to 40-AgNPs. The toxicity pattern was linked to the averagely higher dissolution of 10-AgNPs compared to the larger counterparts. The scanning electron microscopy and X-ray fluorescence analytical techniques were found limited in examining the interaction of the plants with AgNPs at the low exposure concentration used in this study, thus challenging their applicability considering the even lower predicted environmental concentrations AgNPs.

scholarly journals Anticoagulant, thrombolytic and antibacterial activities of Euphorbia acruensis latex-mediated bioengineered silver nanoparticles

2019 ◽  
Vol 8 (1) ◽  
pp. 590-599 ◽  
Author(s):  
Kaushik Roy ◽  
Ambikesh K. Srivastwa ◽  
Chandan K. Ghosh
Keyword(s):  
Silver Nanoparticles ◽  
Analytical Techniques ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Antibacterial Study ◽  
X Ray ◽  
Transmission Electron ◽  
Human Blood Samples ◽  
Green Synthesized Silver Nanoparticles

Abstract In this report, we present a simple and unexplored procedure for green synthesis of silver nanoparticles featuring exudation of Euphorbia acruensis along with the study of its antibacterial and anticoagulant properties. Analytical techniques like ultraviolet visible spectroscopy (UV-Vis), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) were used to analyse the production, crystallinity and morphology of bio-reduced silver nanoparticles. The antibacterial study was performed by following standard disc diffusion method. Most importantly, the anticoagulant and thrombolytic activities of biogenic silver nanoparticles were evaluated by addition of nanoparticles to human blood samples under practical conditions. These green synthesized silver nanoparticles were found to have potent antibacterial, anticoagulant and thrombolytic properties which make them an attractive choice for future medical applications.

scholarly journals Uranium Speciation and Bioavailability in Aquatic Systems: An Overview

2002 ◽  
Vol 2 ◽  
pp. 707-729 ◽  
Author(s):  
Scott J. Markich
Keyword(s):  
Surface Waters ◽  
Metal Ion ◽  
Natural Waters ◽  
Analytical Techniques ◽  
Time Resolved ◽  
Analytical Technique ◽  
Major Form ◽  
Uranyl Carbonate ◽  
Inorganic Ligands ◽  
The Relationship

The speciation of uranium (U) in relation to its bioavailability is reviewed for surface waters (fresh- and seawater) and their sediments. A summary of available analytical and modeling techniques for determining U speciation is also presented. U(VI) is the major form of U in oxic surface waters, while U(IV) is the major form in anoxic waters. The bioavailability of U (i.e., its ability to bind to or traverse the cell surface of an organism) is dependent on its speciation, or physicochemical form. U occurs in surface waters in a variety of physicochemical forms, including the free metal ion (U4+or UO22+) and complexes with inorganic ligands (e.g., uranyl carbonate or uranyl phosphate), and humic substances (HS) (e.g., uranyl fulvate) in dissolved, colloidal, and/or particulate forms. Although the relationship between U speciation and bioavailability is complex, there is reasonable evidence to indicate that UO22+and UO2OH+are the major forms of U(VI) available to organisms, rather than U in strong complexes (e.g., uranyl fulvate) or adsorbed to colloidal and/or particulate matter. U(VI) complexes with inorganic ligands (e.g., carbonate or phosphate) and HS apparently reduce the bioavailability of U by reducing the activity of UO22+and UO2OH+. The majority of studies have used the results from thermodynamic speciation modeling to support these conclusions. Time-resolved laser-induced fluorescence spectroscopy is the only analytical technique able to directly determine specific U species, but is limited in use to freshwaters of low pH and ionic strength. Nearly all of the available information relating the speciation of U to its bioavailability has been derived using simple, chemically defined experimental freshwaters, rather than natural waters. No data are available for estuarine or seawater. Furthermore, there are no available data on the relationship between U speciation and bioavailability in sediments. An understanding of this relationship has been hindered due to the lack of direct quantitative U speciation techniques for particulate phases. More robust analytical techniques for determining the speciation of U in natural surface waters are needed before the relationship between U speciation and bioavailability can be clarified.

Screening-confirmation strategy for nanomaterials involving spectroscopic analytical techniques and its application to the control of silver nanoparticles in pastry samples

2021 ◽  
Vol 246 ◽  
pp. 119015
Author(s):  
Ana I. Corps Ricardo ◽  
Nuria Rodríguez Fariñas ◽  
Francisco J. Guzmán Bernardo ◽  
Rosa C. Rodríguez Martín-Doimeadios ◽  
Ángel Ríos
Keyword(s):  
Silver Nanoparticles ◽  
Analytical Techniques

Viburnum nervosum Leaf Extract Mediated Green Synthesis of Silver Nanoparticles: A Viable Approach to Increase the Efficacy of Anticancer Drug

2020 ◽  
Vol 20 ◽  
Author(s):  
Irfana Zahoor ◽  
Farhat Jan ◽  
Ujjawal Sharma ◽  
Kiran K. Sahu ◽  
Amita Sharma ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Silver Nitrate ◽  
Leaf Extract ◽  
Analytical Techniques ◽  
Therapeutic Interventions ◽  
A431 Cells ◽  
Anti Cancer

Background:: There is an urgent need to devise improved alternatives for the efficient delivery of drugs to develop improved therapeutic interventions against cancers. Nanotechnology based drug delivery vehicles are in-use with obvious issues of toxicity and bio-distribution. Therefore, green synthetic routes are being deployed to replace the conventional nanoparticle formulations for effective drug delivery aiming at developing interventional strategies against cancer. Objective:: A simple, viable and fast approach was used for the green synthesis of silver nanoparticles (AgNPs) using aqueous leaf-extract of Viburnum nervosum (VN) and to explore the anti-cancer potential of the crude extract of VN. Methods:: Silver NPs were synthesized by reacting silver nitrate (AgNO3) with leaf extract of VN. Various analytical techniques were used to characterize the AgNPs. Finally, the anti-cancer potential of VN was observed when delivered through AgNPs. Results:: The surface plasmon spectra for AgNPs exhibited absorbance peak at 445 nm, and Fourier-Transform Infrared Spectroscopy investigation revealed presence of biomolecules acting as an effective reducing and capping agent for converting silver nitrate to AgNPs. Further, our results suggest the spherical size of synthesized AgNPs ranging from 12-17 nm. Moreover, in vitro studies conducted for VN extract with breast (MCF-7) and epidermal carcinoma (A431) cells showed biocompatibility. Conclusion:: Doxorubicin loaded AgNPs documented an increased bioavailability of drug compared to the free drug, suggesting the use of AgNPs as “novel drug delivery vectors”.

Monitoring the Fate and Transformation of Silver Nanoparticles in Natural Waters

2016 ◽  
Vol 97 (4) ◽  
pp. 449-455 ◽  
Author(s):  
Lindsay M. Furtado ◽  
Mirco Bundschuh ◽  
Chris D. Metcalfe
Keyword(s):  
Silver Nanoparticles ◽  
Natural Waters

Effects of silver nanoparticles on bacterial activity in natural waters

2011 ◽  
Vol 31 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Pranab Das ◽  
Marguerite A. Xenopoulos ◽  
Clayton J. Williams ◽  
Md Ehsanul Hoque ◽  
Chris D. Metcalfe
Keyword(s):  
Silver Nanoparticles ◽  
Natural Waters ◽  
Bacterial Activity
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