Biosynthesis of gold nanoparticles using diatoms—silica-gold and EPS-gold bionanocomposite formation

Schröfel, Adam; Kratošová, Gabriela; Bohunická, Markéta; Dobročka, Edmund; Vávra, I.

doi:10.1007/s11051-011-0221-6

Cited by 124 publications

(46 citation statements)

References 46 publications

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“…A number of recent studies with cyanobacteria, purple nonsulfur bacteria, diatoms and Stenotrophomonas sp. have shown that EPS as well as excreted proteins mediate the formation of extracellular nano-particulate gold [64][65][66]. In natural systems gold detoxification via extracellular substances appears to be particular advantageous to biofilm communities, because biofilms contain large amounts EPS and other extracellular substances.…”

Section: Extracellular Compounds For Gold Detoxification-delftia Acidmentioning

confidence: 99%

Geobiological Cycling of Gold: From Fundamental Process Understanding to Exploration Solutions

et al. 2013

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Microbial communities mediating gold cycling occur on gold grains from (sub)-tropical, (semi)-arid, temperate and subarctic environments. The majority of identified species comprising these biofilms are β-Proteobacteria. Some bacteria, e.g., Cupriavidus metallidurans, Delftia acidovorans and Salmonella typhimurium, have developed biochemical responses to deal with highly toxic gold complexes. These include gold specific sensing and efflux, co-utilization of resistance mechanisms for other metals, and excretion of gold-complex-reducing siderophores that ultimately catalyze the biomineralization of nano-particulate, spheroidal and/or bacteriomorphic gold. In turn, the toxicity of gold complexes fosters the development of specialized biofilms on gold grains, and hence the cycling of gold in surface environments. This was not reported on isoferroplatinum grains under most near-surface environments, due to the lower toxicity of mobile platinum complexes. The discovery of gold-specific microbial responses can now drive the development of geobiological exploration tools, e.g., gold bioindicators and biosensors. Bioindicators employ genetic markers from soils and groundwaters to provide information about gold mineralization processes, while biosensors will allow in-field analyses of gold concentrations in complex sampling media.

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Section: Extracellular Compounds For Gold Detoxification-delftia Acidmentioning

confidence: 99%

Geobiological Cycling of Gold: From Fundamental Process Understanding to Exploration Solutions

et al. 2013

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“…It also provides a permanent solution as a result of complete mineralization of the contaminants in the environment (Perelo, 2010). Biosynthesis of different metallic nanoparticles may be triggered by several compounds that are present in marine algae (Mubarak Ali et al, 2011;Schröfel et al, 2011;Vivek et al, 2011;Rajesh et al, 2012;Asmathunisha and Kathiresan, 2013). Green nanotechnology therefore, has attracted a lot of attention and includes a wide range of processes that reduce or eliminate toxic substances to restore the environment (Asmathunisha and Kathiresan, 2013).…”

Section: Introductionmentioning

confidence: 99%

Green synthesis of iron oxide (Fe3O4) nanoparticles using two selected brown seaweeds: Characterization and application for lead bioremediation

2016

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The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe 3 O 4 -NPs) were synthesized using a completely green biosynthetic method by reduction of ferric chloride solution using brown seaweed water extracts. The two seaweeds Padina pavonica (Linnaeus) Thivy and Sargassum acinarium (Linnaeus) Setchell 1933 were used in this study. The algae extract was used as a reductant of FeCl 3 resulting in the phytosynthesis of Fe 3 O 4 -NPs. The phytogenic Fe 3 O 4 -NPs were characterized by surface plasmon band observed close to 402 nm and 415 nm; the obtained Fe 3 O 4 -NPs are in the particle sizes ranged from 10 to 19.5 nm and 21.6 to 27.4 nm for P. pavonica and S. acinarium, respectively. The strong signals of iron were reported in their corresponding EDX spectra. FTIR analyses revealed that sulphated polysaccharides are the main biomolecules in the algae extracts that do dual function of reducing the FeCl 3 and stabilizing the phytogenic Fe 3 O 4 -NPs. The biosynthesized Fe 3 O 4 -NPs were entrapped in calcium alginates beads and used in Pb adsorption experiments. The biosynthesized Fe 3 O 4 -NPs alginate beads via P. pavonica (Linnaeus) Thivy had high capacity for bioremoval of Pb (91%) while that of S. acinarium (Linnaeus) Setchell 1933 had a capacity of (78%) after 75 min. The values of the process parameters for the maximum Pb removal efficiency by Fe 3 O 4 -NPs alginate beads synthesized via P. pavonica (Linnaeus) Thivy were also estimated.Citation: El-Kassas Hala Y, Aly-Eldeen Mohamed A, Gharib Samiha M. 2016. Green synthesis of iron oxide (Fe 3 O 4 ) nanoparticles using two selected brown seaweeds: Characterization and application for lead bioremediation. Acta Oceanologica Sinica,

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“…However, the AuNPs were used in the above-mentioned studies prepared by citrate-reduced AuCl 4 − without any functionalization. To date, a variety of methods have been developed to generate monodisperse AuNPs (Schrofel et al 2011; Moreno-Alvarez et al 2010; English and Waclawik 2012; Singh et al 2010). Recently, AuNPs synthesized with polymers as both the reducing and stabilizing agent were reported to improve their stability and biocompatibility (Sardar et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Chitosan-capped gold nanoparticles for selective and colorimetric sensing of heparin

et al. 2013

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In this contribution, novel chitosan-stabilized gold nanoparticles (AuNPs) were prepared by mixing chitosan with citrate-reductive AuNPs under appropriate conditions. The as-prepared chitosan-stabilized AuNPs were positively charged and highly stably dispersed in aqueous solution. They exhibited weak resonance light scattering (RLS) intensity and a wine red color. In addition, the chitosan-stabilized AuNPs were successfully utilized as novel sensitive probes for the detection of heparin for the first time. It was found that the addition of heparin induced a strong increase of RLS intensity for AuNPs and the color change from red to blue. The increase in RLS intensity and the color change of chitosan-stabilized AuNPs caused by heparin allowed the sensitive detection of heparin in the range of 0.2–60 μM (~6.7 U/mL). The detection limit for heparin is 0.8 μM at a signal-to-noise ratio of 3. The present sensor for heparin detection possessed a low detection limit and wide linear range. Additionally, the proposed method was also applied to the detection of heparin in biological media with satisfactory results.Electronic supplementary materialThe online version of this article (doi:10.1007/s11051-013-1930-9) contains supplementary material, which is available to authorized users.

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Biosynthesis of gold nanoparticles using diatoms—silica-gold and EPS-gold bionanocomposite formation

Cited by 124 publications

References 46 publications

Geobiological Cycling of Gold: From Fundamental Process Understanding to Exploration Solutions

Geobiological Cycling of Gold: From Fundamental Process Understanding to Exploration Solutions

Green synthesis of iron oxide (Fe3O4) nanoparticles using two selected brown seaweeds: Characterization and application for lead bioremediation

Chitosan-capped gold nanoparticles for selective and colorimetric sensing of heparin

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