Biological synthesis of metal nanoparticles

Gericke, Mariekie; Pinches, A.

doi:10.1016/j.hydromet.2006.03.019

Cited by 643 publications

(275 citation statements)

References 21 publications

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“…Lower temperatures and shorter incubation periods resulted in fewer particles formed where an increase in temperature and longer incubation periods resulted in more and slightly larger particles. These findings agree with the physico-chemical properties of nanoparticles as discussed by Gericke and Pinches [39] who stated that the rate of particle formation can be correlated with the incubation temperature where an increase in temperature will allow faster particle formation and the rate of reduction can influence the type of particle formed. Figure 4 illustrates the effect of gold ion concentration on particle formation.…”

Section: Effect Of the Physico-chemical Parameters On Nanoparticle Fosupporting

confidence: 91%

Gold nanoparticle synthesis using the thermophilic bacterium Thermus scotoductus SA-01 and the purification and characterization of its unusual gold reducing protein

et al. 2014

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Nanoparticles are very important materials for implementing nanotechnology in diverse areas and are abundant in nature as living organisms operate at a nanoscale. As nanoparticles exhibit interesting size-and shape-dependent physical and chemical properties, the synthesis of uniform nanoparticles with controlled sizes and shapes is of great importance. Nanoparticles are the end products of a wide variety of physical, chemical and biological processes, some of which are novel and radically different and others of which are quite commonplace. The ability to produce nanoparticles with specific shapes and controlled sizes could result in interesting new applications that can potentially be utilized in areas such as optics, electronics and the biomedical field. In the present study, we have demonstrated the ability of the thermophilic bacterium Thermus scotoductus SA-01 to synthesize gold nanoparticles and determined the effect of the physico-chemical parameters on particle synthesis. Furthermore, a protein purified from this bacterium is shown to be capable of reducing HAuCl 4 to form elemental nanoparticles in vitro. The protein was purified to homogeneity and identified through N-terminal sequencing as an ABC transporter, peptidebinding protein. It is speculated that this protein reduces Au(III) through an electron shuttle mechanism involving a cysteine disulphide bridge. Through manipulation of physico-chemical parameters, it was possible to vary nanoparticles in terms of number, shape and size. This is the first report of a transporter protein from a thermophile with the ability to produce nanoparticles in vitro thus expanding the limited knowledge around biological gold nanoparticle synthesis.

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Section: Effect Of the Physico-chemical Parameters On Nanoparticle Fosupporting

confidence: 91%

Gold nanoparticle synthesis using the thermophilic bacterium Thermus scotoductus SA-01 and the purification and characterization of its unusual gold reducing protein

et al. 2014

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“…Other studies have also indicated that pH plays a key role in controlling particle morphology. Brown et al (2000) reported changes in the shape of gold crystals with changes in pH while studying the role of polypeptides on the resulting gold crystals and Gericke & Pinches (2006) observed that reduction rate regulates the synthesis of different shapes and sizes of gold nanoparticles. They suggested that spherical particle formation is favoured at low reduction rates whereas high reduction rates resulted in the formation of nanorods and platelets.…”

Section: Discussionmentioning

confidence: 99%

Screening of different algae for green synthesis of gold nanoparticles

Parial

Patra

Dasgupta

et al. 2012

European Journal of Phycology

169

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The cyanobacteria Phormidium valderianum, P. tenue and Microcoleus chthonoplastes and the green algae Rhizoclonium fontinale, Ulva intestinalis, Chara zeylanica and Pithophora oedogoniana were exposed to hydrogen tetrachloroaurate solution and were screened for their suitability for producing nano-gold. All three cyanobacteria genera and two of the green algae (Rhizoclonium fontinale and Ulva intestinalis) produced gold nanoparticles intracellularly, confirmed by purple colouration of the thallus within 72 h of treatment at 20 C. Extracted nanoparticle solutions were examined by UV-vis spectroscopy, transmission electron microscopy (TEM) and X-ray diffractometry (XRD). XRD confirmed the reduction of Au (III) to Au (0). UV-vis spectroscopy and TEM studies indicated the production of nanoparticles having different shapes and sizes. Phormidium valderianum synthesized mostly spherical nanoparticles, along with hexagonal and triangular nanoparticles, at basic and neutral pHs (pH 9 and pH 7, respectively). Medicinally important gold nanorods were synthesized (together with gold nanospheres) only by P. valderianum at acidic pH (pH 5); this was initially determined by two surface plasmon bands in UV-vis spectroscopy and later confirmed by TEM. Spherical to somewhat irregular particles were produced by P. tenue and Ulva intestinalis (TEM studies). The UV-vis spectroscopy of the supernatant of other algal extracts indicated the formation of mostly spherical particles. Production of gold nanoparticles by algae is more ecofriendly than purely chemical synthesis. However, the choice of algae is important: Chara zeylanica and Pithophora oedogoniana were found to be unable to produce nanoparticles.

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“…They adsorbed onto Ag-NPs surface stabilizing the nanoparticles and prevent their aggregation. Biosurfactants of biological origin have a lot of positive properties: most of them are rapidly degraded, they are not toxic, their activity is in a wide range of temperature, salinity and acidity [14,15,[17][18][19][20][21].…”

Section: Biosynthesis and Characterization Of Silver Nanoparticlesmentioning

confidence: 99%

“…Bound red formazan was dissolved using 20% acetone and 80% ethanol. The concentration of reduced TTC was determined by measuring the optical density of solution at 500 nm [19]. Each experiment was done in 3 replicates.…”

Section: Ttc Assaymentioning

confidence: 99%

TTC- Based Test as an Efficient Method to Determine Antibiofilm Activity of Silver Nanoparticles

2017

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Abstract. Among metal nanoparticles, silver nanoparticles are a widely used in various life sectors such as in biomedical applications, air and water purification, food production, cosmetics, garments and in various household products. There are several methods for production of silver nanoparticles. Generally, silver nanoparticles can be prepared by chemical methods such as chemical reduction and electrochemical techniques, physical methods, and biological methods such as the use of microorganisms. The biological route of synthesis provides a great diversity in choice for its raw materials such as bacteria, algae, fungi and plants. The aim of the study was to evaluate the tetrazolium/formazan test as a method to determine antibiofilm activity of biological synthetized silver nanoparticles. In this study Bacillus subtilis grown on brewery effluent and produced biosurfactant was used for silver nanoparticles (Ag-NPs) synthesis. The culture supernatants were used in synthesis of Ag-NPs. The formation of nanoparticles accompanied by colour changes of the used reaction system was confirmed by UV-vis spectroscopy. The bacteria isolated from the biofilm of water supply system were used in the evaluation of the antibiofilm activity of biologically synthetized Ag-NPs. To compare the results the commonly used crystal violet assay (CV) for biofilm analysis was applied.

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Biological synthesis of metal nanoparticles

Cited by 643 publications

References 21 publications

Gold nanoparticle synthesis using the thermophilic bacterium Thermus scotoductus SA-01 and the purification and characterization of its unusual gold reducing protein

Gold nanoparticle synthesis using the thermophilic bacterium Thermus scotoductus SA-01 and the purification and characterization of its unusual gold reducing protein

Screening of different algae for green synthesis of gold nanoparticles

TTC- Based Test as an Efficient Method to Determine Antibiofilm Activity of Silver Nanoparticles

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