Synthesis, Characterization of Silver Nanoparticles (AgNPs) from Pluchea ovalis Leaf and Evaluation of its Antimicrobial and Antioxidant Properties
Authors: ahan Shaj , Rani A. Sabitha , Pravalika G. 
Published: December 2024

Pluchea ovalis is an important (significant) medicinal plant that belongs to the Asteraceae family. The present study Silver Nanoparticles (AgNPs) are synthesized, characterized from P. ovalis leaf extract. Also investigated the antimicrobial and antioxidant capabilities of capabilities of Silver Nanoparticles. UV–vis spectroscopy, FTIR, SEM, (XRD), and Zeta potential studies were used to describe the P. ovalis (POL-AgNPs) green synthesis. Colour change from yellow to dark brown and UV–vis absorption spectra's 435 nm absorption band suggested AgNPs generation. SEM analysis showed round and rough-edged crystallite nanostructures with an average particle size of 82 to 114 nm in P. ovalis extract-mediated AgNPs. FTIR showed that AgNPs generation and stability are affected by distinct functional groups -NH(Amide), -CH2(Methylene), and C=O (carbonyl). While XRD spectrum exhibited four Bragg diffraction peaks at 3 9.2218 3981, 6 5.3217, and 7 8 2715 degrees, matching the Fae-centered cubic (fee) structure's facets. Most Zeta Potential readings over +25 mV and below -25 mV are stable. The antioxidant (DPPH) property of green produced of P. ovalis silver nanoparticles (POL-AgNPs)was tested standards (Vitamin C and butylated hydroxytoluene-BHT) at concentrations ranging from 5 to 80 µg/ml. BHT has 65% scavenging activity and vitamin C 98%. This robust finding supports ascorbic acid's antioxidant potential, a dietary antioxidant. POL-AgNPs Methanol is 94% activity. Total Antioxidant Capacity (TAC) of POL-AgNPs, showed 92% total antioxidant activity at doses from 25 to 400 µg/ml, the Ascorbic acid, the main dietary antioxidant, it was 85% active. POL-AgNPs Methanol has 80% total antioxidant activity, compared to 64% and 70% for petroleum ether and chloroform. Antibacterial activity was provided by ampicillin, and different concentrations of POL-AgNPs, (25, 50, 75, and 100 µl) various bacterial strains by agar well diffusion method. Inhibition zone for S. aureus by ampicillin was16 mm at 25 µL 20 mm in 50 µL in, 22 mm in 75 µL in, and 25 mm in 100 µL. The ampicillin zone of inhibition against E. coli was 11, 13, 14, and 16 mm. POL-AgNPs' increasing zones of inhibition against S. aureus were 0.2, 0.6, 5.4, and 11 mm; 0.2, 0.6, 0.8, and 12 mm in (inhibited) S. pneumonia; 0.4, 0.5, 4 mm, and 8 mm in (inhibited) P. aeruginosa. For E. coli, zones are 0.4, 0.5, 6, and 11 mm. S. aureus, E. coli, S. pneumoniae, and P. aeruginosa were inhibited by POL-AgNPs active at a minimum concentration of 200 µg/mL The well diffusion method was used to evaluate POL-AgNPs and Fluconazole's antifungal activity against Candida albicans and Aspergillus niger. C. albicans found that the zones of inhibition, which varied in size from 13 to 22 mm, expanded with time. A. niger was inhibited at 12, 16, 21, and 25 mm. Against A. niger, POL-AgNPs inhibited at 11, 20, 24, and 27 mm. C. albicans had 8,12,16,19 mm inhibitory zones. This research presents a comprehensive examination of the synthesis, characterization of Silver Nanoparticles (AgNPs) from Pluchea ovalis and evaluation of its antimicrobial and antioxidant properties.