Microwave‑assisted synthesis of silver nanoparticles and their application in catalytic, antibacterial and antioxidant activities

Eco-friendly silver nanoparticles (AgNPs) were synthesized using a carboxymethylated gum kondagogu (CMGK) as capping and reducing agent by microwave irradiation method. Synthesized AgNPs were analyzed by TEM, showed spherical in shape with an average particle size distribution of 9 ± 2 nm. XRD results showed that the cubic-structured AgNPs with crystallite size of 8.6 nm. The synthesized CMGK capped AgNPs was tested for catalytic activity using hexacyanoferrate(III) in the presence of NaBH4 and the impacts of catalyst dose and temperature were examined. The synthesized AgNPs demonstrated a huge antibacterial action on both Gram-positive and negative groups of microorganisms with inhibition zone of 23, 25 and 28 mm, respectively, for Bacillus subtilis, Bacillus cereus and Escherichia coli, they showed moderate antibacterial action (zone of inhibition 15 mm) with Pseudomonas aeruginosa. In addition, the ability of the AgNPs scavenging activity with different concentrations was studied using the DPPH radical scavenging.