Antimicrobial and antioxidant activity of Silver, Gold and Silver-Gold Alloy Nanoparticles phytosynthesized using extract of Opuntia ficus-indica

• Published in: Reviews on advanced materials science 2019-01, Vol.58 (1), p.313-326
• Main Authors: Adebayo, Elijah A., Ibikunle, Jelilat B., Oke, Abel M., Lateef, Agbaje, Azeez, Musibau A., Oluwatoyin, Adeboye O., AyanfeOluwa, Ajala V., Blessing, Olowoporoku T., Comfort, Okunlola O., Adekunle, Ogundele O., Badmus, Jelili A., Asafa, Tesleem B., Beukes, Lorika S., Gueguim-Kana, Evariste B., Hakeem, Abbas S.
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Antifungal activity; Antioxidant activity; Nanoparticles
• ISSN: 1605-8127; 1605-8127
• DOI: 10.1515/rams-2019-0039

Aqueous extract of (OF) was employed to reduce salt solutions of silver nitrate, gold chloride and silver nitrate/gold chloride to OFAgNPs, OFAuNPs, and OFAg-AuNPs respectively. Characterization of the particles was carried out using different standard methods, and their antimicrobial and antioxidant activities were also evaluated. The UV-vis spectroscopy showed silver, gold and silver-gold alloys nanoparticles with surface plasmon resonance at 462, 545 and 539 nm, respectively. The significant FTIR peaks: OFAgNPs (3300 and 1635 cm ), OFAuNPs (3288 and 1635 cm ) and OFAg-AuNPs (3307 and 1637 cm ) for synthesized nanoparticles pointed to protein as both capping and stabilizing agent. Generally, particles were spherical with size range of 27-38 nm, 11-28 nm and 15-54 nm for silver, gold and silver-gold alloys nanoparticles respectively. OFAgNPs gave highest antagonistic effects against tested bacteria (35-82%), followed by OFAg-AuNPs (12-75%) and AuNPs (11-48%). The fungal inhibition of 44-70% for OFAgNPs, 42-79% for OFAuNPs and 52-92% for OFAg-AuNPs were obtained. DPPH scavenging activities were obtained as follows: OFAgNPs (52.25–57.50%), OFAuNPs (37.07-59.07%) and OFAg-AuNPs (37.07-63.00%) at tested concentrations of 20–100 µg/ml, which were dose-dependent in comparison with standard BHA (42.57–91.27%) and ascorbic acid (52.13–84.20%). The bleaching inhibition assay of ABTS showed activities of 41.33–61.83% (OFAgNPs), 27.37-50.60% (OFAuNPs) and 32.83-44.33% (OFAg-AuNPs). The synthesized nanoparticles demonstrated an excellent antioxidant and antimicrobial activity. The current study, to the best of our knowledge, is the first time to use to synthesize silver, gold and silver-gold alloys nanoparticles.