Breaking the symmetry of nanoparticles by anisotropic modification & fabrication of 3D sers platform for information storage application

This thesis summarizes my 4 years of graduate research on tuning the plasmon resonance property of nanoparticles by anisotropic modification and fabrication of 3D SERS platform for further information storage applications. In detail, the anisotropic modification is first realized by introducing galvanic replacement at the nanoscale interface through micro-contact printing (Chapter 2). The kinetically controlled reaction leads to the deposition of Au dots on one facet of Ag cubes forming Janus nanostructures, which brings about unique plasmon resonance that can be detected by cathodoluminescence. Moreover, chemical etching is also applied to liquid-liquid interfacial assembled nanoparticles to break the symmetry of nanoparticles through the surface. This controlled etching process can lead to the formation of non-centrosymmetric nanoparticles such as Ag pyramids (Chapter 3). In another research direction, I apply the unique plasmon resonance properties of nanoparticles to the fabrication of efficient, surface-enhanced Raman scattering (SERS) substrates. By integrating two-photon polymerization and Langmuir-Blodgett techniques, I fabricate a 3D SERS substrate to systematically study the effect of tuning physical parameters on the resulting SERS signal intensity (Chapter 4). Based on the optimized parameters in the above study, a further application is developed as micro-barcode patterned SERS substrate is fabricated, which proves to be highly adept in information storage (Chapter 5).DOCTOR OF PHILOSOPHY (SPMS