Controlled Growth of Au@Ag Core-shell Nanoparticles for High-performance Surface Enhanced Raman Scattering Substrate and Application

• Main Author: 戴名柔
• Other Authors: 柯富祥
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/72517083908181969209

碩士 === 國立交通大學 === 材料科學與工程學系奈米科技碩博士班 === 101 === In this study, we report a feasible aqueous chemical method to synthesize Au core-Ag shell nanoparticles (NPs) with uniform size by seeding growth approach. The concentration of Au NPs plays an important role in growing the different thickness of Ag shell. The study reports the fabrication of monolayer Au@Ag core-shell NPs through the self-assembly of Au@Ag core-shell NPs on a 3-aminopropyltrimethoxysilane (APTMS)-modified silicon substrate. Results indicate that the deposition time of Au@Ag core-shell NPs plays a crucial role in determining the density of Au@Ag core-shell NPs on the surface of the silicon substrate. The appropriate thickness of Ag shell and the density of Au@Ag core-shell NPs were optimized to yield the greatest SERS effect in R6G molecule. The design of signaling aptamer utilizes the target-induced switching between an aptamer/DNA duplex and an aptamer/target complex. SERS signal was enhanced upon the hybridization of the Raman reporter-labelled DNA released from the target-induced displacement with the capture DNA immobilized on the silicon substrate with Au@Ag core-shell NPs film. This substrate shows high reproducibility, strong enhancement and low detection limit (1 nM). The enhancement in DNA-based adenosine detection properties shall be advantageous in applications for other aptamer sensing systems.