Green Synthesis of AgNPs Stabilized with biowaste and their antimicrobial activities

Abstract

In the present study, rapid reduction and stabilization of Ag+ ions with different NaOH molar concentration (0.5 mM, 1.0 mM and 1.5 mM) has been carried out in the aqueous solution of silver nitrate by the bio waste peel extract of P.granatum. Generally, chemical methods used for the synthesis of AgNPs are quite toxic, flammable and have adverse effect in medical application but green synthesis is a better option due to eco-friendliness, non-toxicity and safe for human. Stable AgNPs were synthesized by treating 90 mL aqueous solution of 2 mM AgNO3 with the 5 mL plant peels extract (0.4% w/v) at different NaOH concentration (5 mL). The synthesized AgNPs were characterized by UV-Vis spectroscopy, TEM and SEM. Further, antimicrobial activities of AgNPs were performed on Gram positive i.e. Staphylococcus aureus, Bacillus subtilius and Gram negative i.e. E. coli, Pseudomonas aeruginosa bacteria. The AgNPs synthesized at 1.5 mM NaOH concentration had shown maximum zone of inhibition (ZOI) i.e. 49 ± 0.64 in E. coli, whereas Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilius had shown 40 ± 0.29 mm, 28 ± 0.13 and 42 ± 0.49 mm ZOI respectively. The MIC value of 30 μg/mL observed for E. coli Whereas, Staphylococcus aureus, Bacillus subtilius and Pseudomonas aeruginosa had shown 45 μg/mL, 38 μg/mL, 35 μg/mL respectively. The study revealed that AgNPs had shown significant antimicrobial activity as compared to Streptomycin.

Green Chemistry Synthesis of Silver Nanoparticles and Their Potential Anticancer Effects

“…For example, Punica granatum peel extract contains the flavonoids-kaempferol and naringin along with their glycosides. All of these compounds have hydroxyl (-OH) groups that cause the reduction of the Ag + ions, resulting in the formation of AgNPs [67]. A typical reduction is possible by the use of kaempferol as a reducing agent ( Figure 5).…”

“…Synthesis of AgNPs by reaction of AgNO 3 with phytochemicals (concept of this representation was based on[67]). …”

Biological Synthesis of Silver Nanoparticles by Cell-Free Extract ofSpirulina platensis

“…Attachment of nanoparticles by cell wall of bacteria would be due to negative charges and specific functional groups on the bacterial surface. AgNPs after penetration into the bacterial cell may disturb the rigidity of cell wall or lipopolysaccharides membrane and inactivate enzymes functioning and their transport system and generation of H 2 O 2 which results in bacterial death [20].…”

Optical assays based on colloidal inorganic nanoparticles

“…All of these properties are influenced by the size and shape of AgNPs; the smaller the size, the better the activity [187, 193–195]. Similar to AuNPs, AgNPs also have interesting optical properties.…”