Synthesis and spectroscopic characterization of gold nanobipyramids prepared by a chemical reduction method

Abstract

Gold nanobipyramids (NBPs) have attracted much attention because they have potential for applications in smart sensing devices, such as medical diagnostic equippments. This is due to the fact that they show more advantageous plasmonic properties than other gold nanostructures. We describe a chemical reduction method for synthesizing NBPs using conventional heating with ascorbic acid reduction and cetyltrimethylamonium bromide (CTAB)Q+QAgNO3 as capping agents. The product was characterized by ultraviolet Vvisible spectroscopy (UV-Vvis), Fourier transmission infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray powder diffraction (XRD). The results showed that gold nanoparticles were formed with bipyramid shape (tip-to-tip distance of 88.4±9.4 nm and base length of 29.9±3.2 nm) and face-centered-cubic crystalline structure. Optimum parameters for preparation of NBPs are also found.