Extracellular biosynthesis of silver nanoparticles: effects of shape-directing cetyltrimethylammonium bromide, pH, sunlight and additives

Abstract

The work reported in this paper describes the preparation, morphology, stability and sensitivity of Ag-nanoparticles towards sunlight using Allium sativum, garlic extract for the first time. The synthesized silver particles show an intense surface plasmon resonance band in the visible region at 410 nm. The position of the wavelength maxima, blue and red shift, strongly depends on the sunlight and pH. TEM analysis revealed the presence of spherical, different size (from 5.0 to 30 nm) and garlic constituents bio-conjugated, stabilized and/or layered silver nanoparticles. The concentrations of garlic extract, cetyltrimethylammonium bromide, Ag(+) ions and reaction time play vital roles for nucleus formation and the growth processes. Sulfur-containing biomolecules of extract, especially cysteine, are responsible for the reduction of Ag(+) ions into metallic Ag(0). The agglomeration number of the silver nanoparticles (N Ag) and the average number of free electrons per particle (n fe) are calculated and discussed.

Development of a General Fabrication Strategy for Carbonaceous Noble Metal Nanocomposites with Photothermal Property

“…Based on the above XRD analysis, a thermodynamic equilibrium may exist between the reduction of Ag + ions by glucose to form Ag cores and the oxidation of Ag by Br − ions, consistent with previous reports [38][39][40]. For example, Zhou et al [39] demonstrated that Ag nanowires were not formed until the reaction temperature was above 140°C, confirmed by Hussain's work [40]. For the carbonization of carbohydrates (e.g., glucose, saccharide), it was widely accepted that the carbonaceous product can be synthesized at the temperature ranging from 170 to Fig.…”

A review on recent developments in the biosynthesis of silver nanoparticles and its biomedical applications

“…For the green synthesis of silver nanoparticles, plants extracts have been also used as it offers many advantages and also does not require any complex process for the synthesis of AgNPs via plants extract and comparatively easy for large‐scale production (Ahmad et al, 2010; Ahmed et al, 2016; Al‐thabaiti et al, 2015; Ansari et al, 2016; Banerjee et al, 2014; Dinparvar et al, 2020; Hebbalalu et al, 2013; Hussain & Khan, 2014; Jain et al, 2009; Krishnaraj et al, 2010; Leela & Vivekanandan, 2008; Logeswari et al, 2015; MubarakAli et al, 2011; Prasad, 2014; Rahisuddin & Akrema, 2016; Song & Kim, 2009; Vijilvani et al, 2020). Mainly the parts of the plant used for the synthesis are leaves, root, stem, bark, flower and fruit (Meena et al, 2020).…”

Synthesis of Citrate-Stabilized Silver Nanoparticles Modified by Thermal and pH Preconditioned Tannic Acid

“…Recent studies have shown that control over basic citrate methods may be improved by the use of selected organic additives [ 12 ], which, having greater reducing capacity than citrate and inducing more rapid nucleation, lead to a smaller but narrower final size distribution as compared to citrate alone. In some cases, it has been hypothesized that the use of citrate alone may cause heterogeneous growth (wires, rods, etc.)…”