BIOSYNTHESIS AND CHARACTERIZATION OF GOLD NANOPARTICLES FROM CEIBA PENTANDRA (L.) GAERTN BARK AND EVALUATION OF ITS ANTIBACTERIAL AND ANTICANCER ACTIVITY

The present investigation was aimed at synthesis, characterization and in-vitro antibacterial and anticancer activities of synthesized gold nanoparticles using bark extract of Ceiba pentandra (L.) Gaertn. The synthesized AuNPs were confirmed by a UV-vis spectrometer through observing the surface plasmon resonance peak at 535 nm. Various other techniques, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Selected area electron diffraction (SAED), and High- resolution transmission electron microscopy (HR-TEM) were also employed in the demonstration of the AuNPs properties. The synthesized gold nanoparticles were highly stable, spherical in shape, while other particles had irregular circles without uniform edges with average sizes of 20-48 nm. By using the agar well diffusion method, an attempt was made to evaluate the antibacterial activity of the metal nanoparticles against human pathogenic bacteria.  AuNPs showed efficient antibacterial activity, which was found to be more pronounced against gram-negative bacteria than gram-positive ones. Through MTT assay, cytotoxicity effects of the synthesized AuNPs were tested against HCT-116 colon cancer cell lines with an IC₅₀ inhibitory concentration of 40 µg/ml.