Green synthesis of silver nanoparticles using carob leaf extract and its antibacterial activity

Abstract

Investigations were carried out to compare the effectiveness of compounds such as sodium nitrite, trisodium citrate (TSC) and TSC-zinc acetate to inhibit the corrosion of steel rebar in simulated concrete interstitial solution contaminated with chloride and to explain the mechanism of corrosion inhibition on reinforcing steel by these systems. Inhibition efficiency of these systems was studied by electrochemical techniques such as potentiodynamic polarization and half cell potential measurements. Electronic spectral studies of simulated pore solution and FT-IR spectral investigations of the film deposited on steel surface were carried out for understanding the mechanism of corrosion inhibition. Microscopic surface analysis was conducted to obtain the surface morphological behaviour of steel rebar. TSC alone was not exhibited good corrosion inhibition at very low and high concentrations according to electrochemical studies. However, in the presence of zinc acetate, corrosion protection efficiency of TSC increased appreciably. When comparing with sodium nitrite, TSC in the presence and absence of zinc acetate displayed good corrosion inhibition efficiency. Among a number of samples, TSC 100 ppm-zinc acetate 50 ppm combination showed maximum corrosion inhibition efficiency on steel rebar in simulated concrete interstitial solution.Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s4009 0-018-0142-7) contains supplementary material, which is available to authorized users.

Biosynthesis, characterization and antibacterial activity of silver nanoparticles from Aspergillus awamori

“…Thus, our result provides a promising spectroscopic signature of nanoparticle formation. The synthesis was evidently expressed by the bioreduction of silver ions into corresponding NPs which may be due to the presence of the nicotinamide adenine dinucleotide hydrogen-dependent enzyme, nitrate reductase that probably acts as an electron carrier in the reduction process [7]. The results of the present investigation revealed that several hydroquinones with redox potential in the microbial cells could also act as electron shuttle in the reduction mechanism and play a role in the formation of SNPs [17].…”

“…Depending on their size shape and distribution they exhibit various properties. Different approaches have been used for the synthesis of NPs [7]. In recent past, a great deal of intensive effort has been put into the synthesis of NPs using plants and microorganisms.…”

“…Fungal mediated synthesis of SNPs has been done by a number of researchers so far. Fusarium oxysporum [7], Aspergillus fumigates [9], Fusarium semitectum [10], Aspergillus niger [11], Cladosporium cladosporioides [12], Penicillium brevicompactum [13], and Aspergillus clavatus [14] have been previously described. An extensive intracellular and extracellular study has been conducted on the biosynthesis of SNPs by Aspergillus species.…”

Artemisia herba-alba Asso eco-friendly reduced few-layered graphene oxide nanosheets: structural investigations and physical properties

“…Recent research in this field has reported the use of different plant leaf extracts for synthesizing silver nanoparticles, such as Gloriosa superba L. (47), Citrus limon L. (48), Carob (49) and Tephrosia purpurea L. (50). On the other hand, the synthesis of gold nanoparticles was reported using a tea leaf extract (51), Pelargonium graveolens (PeG) (52), Punica granatum (PuG) (53), Salvia offiinalis (SO) (54) and Morinda citrifolia roots extracts (55).…”

Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast (Saccharomyces cerevisiae) extract

“…The biological route was chosen over common chemical and physical procedures because it is an easy, fast and eco-friendly option and does not involve any costly instrument or hazardous by-product as well (Awwad et al 2013). In recent times, plant-mediated (Banerjee et al 2014;Roy et al 2013;Phanjom et al 2012) and microbemediated (Sudha et al 2013;Malarkodi et al 2013;Honary et al 2013) synthesis procedures are frequently used for nanoparticle synthesis.…”