Green Synthesis of Silver Nanoparticles From Three Endemic Plants in Türkiye: Antioxidant, Antimicrobial, and Larvicidal Activities

ABSTRACT Green synthesis of silver nanoparticles (AgNPs) using three plant extracts, namely, Centaurea ensiformis (CENT), Origanum hypericifolium (ORIG), and Paeonia turcica (PAE), was carried out. Fabrication of AgNPs via reductive and stabilizing capabilities of phytochemicals was confirmed by UV–vis spectroscopy under variable conditions including pH, temperature, extract volume, metal ion concentration, and reaction time. Surface plasmon resonance (SPR) peaks were observed in the range of 400–450 nm. Fourier transform infrared spectroscopy (FTIR) revealed the presence of functional groups that belong to phytoconstituents involved in the synthesis of AgNPs. The shape, morphology, elemental composition, size distribution, zeta potential, and crystal properties of AgNPs were determined using scanning electron microscopy (SEM), energy dispersive x‐ray spectroscopy (EDX), dynamic light scattering (DLS), and X‐ray diffraction (XRD), respectively. AgNPs from PAE and ORIG extracts were able to scavenge DPPH (92.7 ± 1.99% and 90.9 ± 1.79%) effectively and PAEAgNP scavenged ABTS by 89.9 ± 1.54%. Antimicrobial activity was determined by agar‐well diffusion method and CENTAgNP showed antibacterial and antifungal activities. All AgNPs were active against Staphylococcus aureus 25923, Pseudomonas aeruginosa PAO1, and Escherichia coli 25922. Larvicidal activity was conducted using Aedes aegypti larvae exposed to AgNPs for 48 h and PAEAgNP demonstrated the highest mortality with an LC 50 value of 5.034 ppm.