Artemisia Afra (Ariti) Leaf Extract Mediated Ag/SiO2 Nanocomposites for Antibacterial and Antifungal Activity

Abstract

Increasing case of drug resistance, unwanted side effects of existing antibiotics, and the reappearance of earlier known infection have demanded the need for new, safe, and effective antimicrobial agent. For this reason, Nanotechnology is the new advanced technology for increasing new antibiotic production. This study aimed to synthesize environmentally friendly Ag/SiO2 NCs for antibacterial and antifungal activity by a green method. Artemisia Afra (Ariti) is used as a reducing and capping agent in the NPs and NCs synthesis method. The synthesized materials were characterized using Uv-Visible spectroscopy, XRD, FTIR, and SEM. UV-Visible study revealed the optical band gap energy of NPs and NCs was estimated with different concentrations. The XRD pattern of Ag and SiO2 showed peaks, confirming the formation of the silver FCC structure and amorphous structure(non-crystalline) of SiO2 NCs.The XRD pattern also confirmed the formation of Ag/SiO2 NCs.The average crystallite size of the Ag NPs and Ag/SiO2 NCs estimated from the XRD diffraction pattern using Debye Scherrer’s formula was 16.68 and 8.99nm. The FTIR analysis shows the presence of hydroxyl, carbonyl, alkyl, amide, alcohol, and nitro functional group in NPs and NCs.The porosity of SiO2 NPs, the spherical shape of Ag NPs, and their combination of the morphology structure were confirmed by SEM analysis. The antimicrobial activity of the biosynthesized NPs and NCs was screened against two Gram-positive bacteria (Streptococcus pyogenes and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungal strains (Candida albicans) using the Agar disc diffusion method. Ag/SiO2 NCs showed better antibacterial activity, with maximum zone inhibition values of 15 mm and 16 mm at 10 mg/mL dosage towards Gram-negative and Gram-positive bacteria, respectively. The best antifungal activity was displayed by Candida albicans at Ag/SiO2 NCs with a maximum zone inhibition of 14mm at the concentration of 10mg/mL. The MIC and MBC was recorded for both bacterial activities.