Photochemical synthesis of metallic silver nanoparticles using Pistacia khinjuk leaves extract (PKL@AgNPs) and their applications as an alternative catalytic, antioxidant, antibacterial, and anticancer agents

In recent decades, antimicrobial resistance of different bacteria against various antibiotics and contamination of water resources by various dyes has been one of the most important human problems. Therefore, in this research, biogenic silver nanoparticles were synthesized using nontoxic and rapid approach using Pistacia khinjuk leaves extract (P. khinjuk) as compatible and safe reducing agent (PKL@AgNPs). Nanoparticle optimization experiments were performed at different times, temperatures and concentrations in order to achieve the most optimal conditions. The biosynthesized AgNPs were characterized in terms crystalline, morphology and structural. The Fourier-transform infrared spectroscopy (FT-IR) spectra showed that the phenol compounds present in the P. khinjuk leaves extract were responsible for silver ion (Ag+) reduction and stabilization of AgNPs (Ag0). X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) analysis results revealed that the product were face-centered cubic structure, homogeneous, uniformly, oval-like and spherical morphology with size of about 35–45 nm. The biosynthesized AgNPs exhibited a high photocatalytic activity for the degradation of the methylene blue (MB) and methyl orange (MO) as hazardous contaminants. The degradation efficiency of PKL@AgNPs for MB and MO pollutants were 93.2% and 85.37% under UV and 75.18% and 70.03% under sun-light irradiations, respectively. Furthermore, the PKL@AgNPs showed strong antibacterial and antifungal activities against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus mutans, Streptococcus mitis, Enterococcus faecalis, and Candida albicans with minimum inhibitory concentration (MIC) values of 0.58, 0.58, 0.58, 1.17, 2.34, 1.17, and 0.15 μg ml−1, respectively. The antioxidant activity of PKL@AgNPs was calculated and the results revealed that the percentage of DPPH inhibition increased (3.8% to 69.9%) with increasing the concentration of nanoparticles. Also, the PKL@AgNPs also revealed significant anticancer activity on k562 as a human leukemia cancer cell line (IC50 = 2.69 μg ml−1). All these investigations revealed that silver nanoparticles synthesized by natural extract have the potential to use as low-cost and efficient nanoparticles for environmental and biomedical applications.