A novel method to prepare gold-nanoparticle-modified nanowires and their spectrum study

In this paper, a practical and mild sol–gel self-assembly method was successfully developed for the synthesis of plain and gold-nanoparticle-modified silica nanowires (AuSiNWs). In this new method, the 3-mercaptopropyltrimethoxysilane (MPTMOS) was used as the key linker through disulfide bonds and mediated the reorganization of the particles into elongated clusters. The high surface strain energy of the silica nanoparticles, as a driving force, deformated the interconnected nanoparticles into nanowire. All the procedures were performed in solution and under mild conditions (below 100 °C at atmosphere pressure), and no special apparatus was needed. This promising method made it possible to synthesize the SiNWs in large scale. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM) were used to characterize the obtained nanostructures. The microscopy was used to investigate the products at each stage in the synthetic process and the formation mechanism of the new method was discussed. The investigated AuSiNWs displayed an intensive absorption at 528 nm, characteristic of gold nanoparticles, and a strong luminescence peak at 440 nm.