Evaluation of the Antioxidant, Antibacterial, and Insecticidal Potential of Plant‐Derived AgNPs Synthesized Using Cupressus arizonica Greene

ABSTRACT

The combined use of plant‐derived extracts and silver ions in the green synthesis of nanoparticles confers superior performance in multiple biological activities. The primary objective of this study was to synthesize silver nanoparticles (AgNPs) from the aqueous extract of Cupressus arizonica (CA). The characterization of AgNPs (CA‐AgNPs) was performed using UV–vis, FTIR, XRD, SEM, EDX, and TEM. Antioxidant, antibacterial, and insecticidal activity tests were applied to CA‐extract and CA‐AgNPs. Both samples exhibited antioxidant activity. The findings indicate that CA‐extract did not affect Staphylococcus aureus and Escherichia coli bacteria, whereas CA‐AgNPs inhibited the growth of S. aureus (9.33 ± 0.57 mm) and E. coli (8.16 ± 0.28 mm) at 5000 µg/mL concentration. The insecticidal effects of CA‐extract and CA‐AgNPs against the pest Sitophilus granarius (L.) were evaluated. As the duration of insecticidal application increased, the concentration required for mortality decreased. In the topical assay, after 72 h, the LC50 of CA‐AgNPs was 341.98 µg/mL, whereas the LC50 of the CA‐extract was 1301.44 µg/mL. During contact testing, the LC50 values of CA‐AgNPs and CA‐extract for 72 h of exposure were calculated as 2353.29 and 4090.17 µg/mL, respectively. Consequently, green‐synthesized AgNPs show promising potential for antioxidant, antimicrobial, and plant health applications.