Microwave-Mediated Synthesis of Gold Nanoparticles Using Coconut Water

We report the synthesis of gold nanoparticles using coconut water through microwave irradiation. Synthesis was found to be very rapid with an optimum time of 17 s. The particles obtained were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and atomic force microscopy (AFM). The synthesized gold nanoparticles were found to be mostly spherical with an average diameter of 10.5 ± 5 nm. The crystalline nature of gold nanoparticles was confirmed by X-ray diffraction (XRD) patterns. Fourier transform infrared (FTIR) analysis suggested the presence of organic biomolecules on the surface of the gold nanoprticles, which may be responsible for the stability of the particles. Cytotoxicity of the gold nanoparticles was tested on two human cancer cell lines, HeLa (human cervical cancer) and MCF-7 (human breast cancer), and found to be nontoxic, which thus proved their biocompatibility. The method exploits a cheap and easily available biomaterial that can be directly used for the synthesis of gold nanoparticles and has the potential for the synthesis of metallic nanoparticles other than gold.