<i>Theobroma Cacao</i> pod husk extract mediated gold nanoparticles: synthesis, characterization and evaluation of their cytotoxicity activity using brine shrimp hatching assay

Abstract The advancement of nanotechnology has led to the exploration of environmentally sustainable methodologies for nanoparticle synthesis, particularly emphasizing the significance of green chemistry. Among these, the green synthesis of gold nanoparticles (AuNPs) using natural extracts has gained attention with respect to their potential biomedical applications. This study presents a novel method for the green synthesis of AuNPs employing CPH extract, which is sustainable and environmental-friendly. The synthesized CPH–AuNPs exhibited remarkable stability as evident from different characterization techniques, including UV–visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Transmission Electron Microscopy. These analyses revealed that the CPH–AuNPs were predominantly homogeneous, spherical shaped with an average particle size and crystallite size of 16 nm and 17 nm, respectively. UV–Vis spectroscopy confirmed successful synthesis of CPH–AuNPs, with absorption peak stabilizing at 533 nm. TEM technique further confirmed the long–term stability feature of the synthesized nanoparticles. Additionally, the biosafety of CPH–AuNPs assessed using brine shrimp ( Artemia salina ) hatching assay, revealed 47 % hatching rate at the least concentration of 62.5 µg mL −1 , thereby underscoring their high biocompatibility. This research paves the way for the development of novel AuNPs synthesized using isolated polyphenols from CPH extract, with promising implications for their application in the biomedical field.