Seripheidium quettense mediated green synthesis of biogenic silver nanoparticles and their theranostic applications

Green synthesis of nanoparticles is an emerging field of nanotechnology, preferred over physical and chemical synthesis owing to their safety, cost-effectiveness nature, bio-compatibility, eco-friendly and scalable properties. The present study includes Seripheidium quettense aqueous extract mediated green synthesis, optimization of silver nanoparticles (Sq-AgNPs) and their pharmacological evaluations. Synthesis was done considering various optimization parameters including concentrations of AgNO3, pH of the reaction mixture, extract to precursor ratio and temperature. Biosynthesis was carried out using our already optimized conditions. UV–visible spectrophotometer, FTIR, XRD and SEM analysis were used for characterization of Sq-AgNPs. The synthesized Sq-AgNPs (49.96–54.36 nm) were evaluated for their antibacterial, antifungal, anticancer and hemolytic potentials. The maximum antibacterial activity was found against Escherichia coli, Klebsiella pneumonia and Bacillus subtilis with their MICs of 11.1, 33.3 and 33.3 μg/mL, respectively. Aspergillus nigar was found as the most susceptible fungal strain with the highest zone of inhibition (13.2 ± 0.72 mm). Sq-AgNPs inhibited proliferation of human liver cancer cell lines (HepG2) with median lethal concentration (IC50s) of 62.5 µg/mL. Results of the hemolytic assay showed that SqNPs are bio-compatible and have less effect on erythrocytes even at high concentration of 100 µg/mL.