Characterization of biosynthesized gold nanoparticles from aqueous extract of Chlorella vulgaris and their anti-pathogenic properties

Abstract

In this study, biosynthesis of self-assembled gold nanoparticles (GNPs) was accomplished using an aqueous extract of green microalga, Chlorella vulgaris. The optical, physical, chemical and bactericidal properties of the GNPs were investigated to identify their average shape and size, crystal nature, surface chemistry and toxicity, via UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and antimicrobial activity. The sizes of the spherical selfassembled cores of the synthesized GNPs ranged from 2 to 10 nm. The XRD patterns showed a (111) preferential orientation and the crystalline nature of the GNPs. The results of the FTIR analysis suggested that the peptides, proteins, phenol and flavonoid carried out the dual function of effective Au III reduction and successful capping of the GNPs. Human pathogen Candida albicans and Staphylococcus aureus were susceptible to synthesized aqueous GNPs. Thus, biosynthesis, stabilization and self-assembly of the GNPs by Chlorella vulgaris extract can be an example of green chemistry and effective drug in the medicinal field.

Phycosynthesis and Enhanced Photocatalytic Activity of Zinc Oxide Nanoparticles Toward Organosulfur Pollutants

“…4B) 16 . This results are in compliance with several reports indicating biogenic synthesis of nanoparticles such as palladium nanocrystals 16 , and gold 34 nanoparticles which indicated that diverse metabolites present in microalgae extracts such as polyphenols, sugars, terpenoids, proteins, phenolic acids, and enzymes are key responsible for reduction and stabilization of green nanoparticles 34,35 .

Figure 4FTIR spectrum of Chlorella aqueous extract ( A ), and biosynthesized ZnO NPs ( B ).

Figure 5Schematic illustration of the possible mechanism for the biogenic synthesis of ZnO NPs using aqueous Chlorella extract (algae-derived carbohydrate as bioreducing agent model).

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Plant-Mediated Biosynthesis and Photocatalysis Activities of Zinc Oxide Nanoparticles: A Prospect towards Dyes Mineralization

“…However, the mechanism of biosynthesis of nanoparticles is still not well understood and requires more studies. e most plausible general mechanism is concluded that the functional groups existing in the plant extract such as alcohol, polyphenols, flavonoids, aromatic, and aliphatic amines play an important role in the green synthesis of ZnO NPs [80][81][82]. e aqueous extract of the plant that contains a high amount of organic components contributes to the metallic ion reduction processes.…”

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“…2 showed a distinct peak in the range of 3336, 2128, 1636, and 722 cm -1 representing the presence of capping molecules with the nanoparticles. The FTIR a major peak, was obtained at 1,636 cm -1 indicating the presence of amide-I and amide II bonding from capped peptides; Annamalai et al, reported similar results 35 . Fig.…”