A new route to obtain high-yield multiple-shaped gold nanoparticles in aqueous solution using microwave irradiation.

A highly effective, very fast microwave method is described to synthesize shape controlled gold nanoparticles in the presence of 2,7-dihydroxy naphthalene (2,7-DHN) as a new reducing agent under microwave heating for 60-90 s. The growth of the particles with different shapes (spherical, polygonal, rod, and triangular/prisms) was directed by the surfactant to metal ion molar ratios and the concentration of 2,7-DHN. The evolved nanorods and nanoprisms are fairly small in diameter, and the particle size and shape were successfully tuned just by varying the molar ratios of the reactants. The process presented here can be extended to the synthesis of other nanomaterials with desired size and shape and might find a variety of applications in wide areas, such as catalysis, clinical and diagnostic medicine, and nanoelectronics.