Green Synthesis of Au Nanostructures at Room Temperature Using Biodegradable Plant Surfactants

One-step green synthesis of gold (Au) nanostructures is described using naturally occurring biodegradable plant surfactants such as VeruSOL-3 (mixture of d -limonene and plant-based surfactants), VeruSOL-10, VeruSOL-11, and VeruSOL-12 (individual plant-based surfactants derived from coconut and castor oils) without any special reducing agent/capping agents. This greener method uses water as a benign solvent and surfactant/plant extract as a reducing agent. Depending upon the Au concentration used for the preparation, Au crystallizes in different shapes and sizes to form spherical, prisms, and hexagonal structures. Sizes vary from the nanometer to micrometer scale level depending on the plant extract used for preparation. Synthesized Au nanostructures were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and UV spectroscopy.