Antibacterial and Larvicidal Activity of Silver Nanoparticles Synthesized by the Leaf Extract of Andrographis serpyllifolia Wight

Green synthesizes of nanoparticles made a curiosity in the field of nanobiotechnology and they have a wide range of application. In this investigation, the leaf extract of Andrographis serpyllifolia was used to synthesis silver nanoparticles as a greener approach. These green silver nanoparticles characterized by UV-Spectrophotometer, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), Transmission Electron Microscope (TEM), Zeta potential and particle size analysis. The silver nanoparticles were of spherical in nature with a minimum of 3.4 nm to a maximum of 71.6 nm with the average size of 24.1 nm. The larvicidal study showed that the AgNPs were highly active against the Culex quinquefasciatus larvae and the LC50 value observed was 68.889 µg/ml and LC90 value observed was 392.117. In addition, the antimicrobial study revealed that the A. serpyllifolia intervened AgNPs have shown prominent activity against the clinical pathogens viz., Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas fluorescens, and Escherichia coli. The maximum zone of inhibition observed against the S. pneumoniae was 21.33 ± 0.88 mm (75 µg/ml). Whereas, the lowest was observed against the S. aureus 14.66 ± 0.57 mm (25 µg/ml). The A. serpyllifolia mediated AgNPs demonstrated prominent bioactivity and used to control the emerging mosquito population and pathogenic microorganisms.