Noble Metallic Nanoplates:Synthesis,Assmebly And Their Applications In SERS

Recently, noble metal nanoparticles have attract more interests around the world due to their unique optical or electronic properties. Among these nanomaterials, gold nanoplate is one kind of promising anisotropic nanoparticles, which is ascribed to their structure-and environment-dependent optical features, their anisotropic surface energetics, and the emergence of reliable synthetic methods for producing them with control over their edge lengths and thickness. In contrast with individual nanoparticles, the self-assembled nanostructures of nanopartices behave new unique physical and chemical properties, leading to applications in optics, chemical and biosensing. Therefore, applying anisotropic noble metallic nanoassembly as highly active substrates in SERS is becoming an important analytical technique.The gold nanoplate has been successfully synthesized by seed-mediated approach and the gold nanoplate-in-shell with high purity has been prepared via a facile two-step synergistic protocol. Based on the gold nanoplate and their derivatives, three kinds of self-assembled superstructures have been constructed in the thesis. The monolayer gold nanoplates and nanoplate-in-shell substrates were yielded via layer-by-layer approach, and they have been used as direct readout SERS for multiplex recognition of pesticides. Regiospecific core-satellite assembly of gold nanoplate/gold nanorod has been fabricated via ss-DNA hybridization, and it has been used to monitor the catalytic coupling reaction of4-amino thiophenol(p-ATP). We also used the layer-by-layer approach to fabricate carbon sphere/gold nanoplates3D assembly, and designed a novel stategy for optical detection of arsenic.