Fabrication and Characterization of Noble Crystalline Silver Nanoparticles from Ceropegia bulbosa Roxb Root Tuber Extract for Antibacterial, Larvicidal and Histopathology Applications

The study was designed to reduce silver ions in to crystalline silver nanoparticles through bio-green route using Ceropegia bulbosa Roxb root tuber extract and characterized by UV-Vis spectroscopy, X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emissionscanning electron microscopy (FE-SEM) with EDS mapping and High-resolution transmission electron microscopy (HRTEM) and investigates the larvicidal activity of Aedes albopictus. The surface plasmon resonance and was observed at 428 nm in UV-Vis spectrum. The XRD analysis of silver nanoparticles confirms four strong peaks at 2 theta ranges assigned to the 111, 200, 220 and 311, respectively. The FTIR spectrum proves the presence of various functional groups in the biomolecules which perform as a capping energy for the nanoparticles formations. The SEM-EDS mapping and HRTEM images prove silver nanoparticles are in spherical shape; the average particle size was similar to 4.16 +/- 0.7 nm with exact elemental composition. The antibacterial and larvicidal activity of synthesized silver nanoparticles demonstrated excellent activity against tested bacteria and the larvae of Ae. albopictus with LC50 values of 0.507 mu g/ml and LC90 value of 1.248 mu g/ml, respectively. Histopathology of Ae. albopictus treated with silver nanoparticles for IVth stage larvae after 24 h exposure at the maximum mortality concentration (250 mu g/ml) proved that the region of the hindgut, mid gut, epithelial cells and cortex were severely affected.