Development and optimization of hierarchical structures on nanosphere substrates for surface enhanced Raman spectroscopy.

• Main Author: Quan, Lam Zhung.
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Nanotechnology; DRNTU::Science::Physics::Optics and light
• Online Access: http://hdl.handle.net/10356/45414
• Institution: Nanyang Technological University

Surface Enhanced Raman Scattering (SERS) yields gigantic enhancement of inherently weak Raman signal by an intensive interaction of incident light with a noble metallic surface having nanometric roughness. In the past, the synthesis of gold nanoparticles through reduction process has been reported and shown to exhibit strong Raman enhancement due to its plasmonic properties which are governed by size and shape. However, the appropriate control of undesired particles aggregation in dynamic chemical conditions remains a challenge. On the other hand, the patterned SERS solid substrate is more robust and hence such substrate is preferably used as ex vivo biological sensor. Metal Film over Nanosphere (MFON) is a substrate that can be easily fabricated and its larger surface area serves as a good platform for sensing. Nowadays, MFON is fabricated by dispersing orderly-packed polystyrene beads on a glass surface followed by metal deposition. In this report, novel SERS substrate with a unique architecture is introduced and investigated by anchoring colloidal gold nanoparticles onto the solid gold substrate making use of thiol-based linker molecule.