LAUSR

Abstract A green chemical approach to the synthesis of gold nanoparticles from the Caulerpa racemosa and its biomedical applications are reported. The C. racemosa mediated synthesized gold nanoparticles (Cr@AuNPs) were characterized by various spectral and microscopy techniques. The Cr@AuNPs exhibited a surface plasmon resonance (SPR) peak at 528 nm in UV–Vis spectrum. X-ray diffraction analysis confirmed the crystalline nature and face-centered cubic (fcc) structure of Cr@AuNPs. The presence of phytochemical constituents in the aqueous extract of C. racemosa that involves the major role in Cr@AuNPs synthesis which was confirmed by FT-IR analysis. Further, FESEM and HRTEM results confirmed that the Cr@AuNPs were spherical-to-oval in shape, and the size was ranged from 13.7 to 85.4 nm. The synthesized Cr@AuNPs effectively controlled the growth of human colon adenocarcinoma (HT-29) cells, and it exhibited the IC50 at 20.84 μg/ml. Similarly, the green synthesized Cr@AuNPs demonstrated admirable antibacterial activity against A. veronii than S. agalactiae. Further, the synthesized Cr@AuNPs exhibited non-toxic effects on Artemia nauplii, even at high concentration of Cr@AuNPs (100 μg/ml). The above findings deliver a strong basis for future studies into drug development for cancer and bacteria.