Using aqueous cyanobacterial extracts in the synthesis of silver nanoparticle is looked as green, ecofriendly, low priced biotechnology that gives advancement over both chemical and physical methods. In the current study, an aqueous extract of Oscillatoria limnetica fresh biomass was used for the green synthesis of Ag-NPs, since O. limnetica extract plays a dual part in both reducing and stabilizing Oscillatoria-silver nanoparticles (O-AgNPs). The UV-Visible absorption spectrum, Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM) and scanning electron microscope (SEM) were achieved for confirming and characterizing the biosynthesized O-AgNPs. TEM images detected the quasi-spherical Ag-NPs shape with diverse size ranged within 3.30–17.97 nm. FT-IR analysis demonstrated the presence of free amino groups in addition to sulfur containing amino acid derivatives acting as stabilizing agents as well as the presence of either sulfur or phosphorus functional groups which possibly attaches silver. In this study, synthesized Ag-NPs exhibited strong antibacterial activity against multidrug-resistant bacteria (Escherichia coli and Bacillus cereus) as well as cytotoxic effects against both human breast (MCF-7) cell line giving IC50 (6.147 µg/ml) and human colon cancer (HCT-116) cell line giving IC50 (5.369 µg/ml). Hemolytic activity of Ag-NPs was investigated and confirmed as being non- toxic to human RBCs in low concentrations.

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Synthesis and biological characterization of silver nanoparticles derived from the cyanobacterium Oscillatoria limnetica.

Algae-based metallic nanoparticles: Synthesis, characterization and applications.

Nanotechnology has become a trending area in science and has made great advances with the development of functional, engineered nanoparticles. Various metal nanoparticles have been widely exploited for a wide range of medical applications. Among them, gold nanoparticles (AuNPs) are widely reported to guide an impressive resurgence and are highly remarkable. AuNPs, with their multiple, unique functional properties, and easy of synthesis, have attracted extensive attention. Their intrinsic features (optics, electronics, and physicochemical characteristics) can be altered by changing the characterization of the nanoparticles, such as shape, size and aspect ratio. They can be applied to a wide range of medical applications, including drug and gene delivery, photothermal therapy (PTT), photodynamic therapy (PDT) and radiation therapy (RT), diagnosis, X-ray imaging, computed tomography (CT) and other biological activities. However, to the best of our knowledge, there is no comprehensive review that summarized the applications of AuNPs in the medical field. Therefore, in this article we systematically review the methods of synthesis, the modification and characterization techniques of AuNPs, medical applications, and some biological activities of AuNPs, to provide a reference for future studies.

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Multifunctional Gold Nanoparticles: A Novel Nanomaterial for Various Medical Applications and Biological Activities

A review on biosynthesis of metal nanoparticles and its environmental applications

Algae-mediated biosynthesis of inorganic nanomaterials as a promising route in nanobiotechnology – a review

As nanotechnology is expanding to several commercial fields, there is a need of ecofriendly and energy-efficient methods for the synthesis of nanoparticles. Algae have been discovered to reduce metal ions and subsequently for the biosynthesis of nanoparticles. Since algae-mediated biosynthesis of nanoparticles is an ecofriendly, economical, high-yielding, expeditious and energy-efficient method, a large number of studies have been published in the last few years. This review article therefore is focused on recent progress on the utilization of algae of various classes, viz., Cyanophyceae, Chlorophyceae, Phaeophyceae, Rhodophyceae, etc. for the synthesis of nanoparticles, their characterization and the possible mechanisms involved.

Algae as crucial organisms in advancing nanotechnology: a systematic review

Nickel oxide nanoparticles (NiO NPs) were synthesized by adopting green route with a nontoxic aqueous phytoextract of guava leaves for their application as supercapacitor electrodes. The characteristic UV absorption peak for NiO NPS was observed at 266 nm. X-ray diffraction (X-RD) study confirms the crystalline nature of biosynthesized nanoparticles with cubic face-centered crystal structure. Coral-like shape of nanostructures of NiO is demonstrated by scanning electron microscopy (SEM). Biosynthesized NiO nanoparticles are further characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and differential thermal analysis (DTA). The electrochemical properties and cycle performance of supercapacitor device using NiO nanoparticles as electrode material were investigated by cyclic voltammetry with different concentrations of aqueous potassium hydroxide (KOH) electrolyte. The NiO NPs electrode exhibited specific capacitance of 85.31 F/g in the potential window of 0.8 V at the scan rate 2 mV/s with 5 M KOH electrolyte.

Pushpa Singh

Papers

Algae as crucial organisms in advancing nanotechnology: a systematic review

Bioinspired synthesis of nickel oxide nanoparticles as electrode material for supercapacitor applications