Surface-Enhanced Raman Scattering Based on Graphene-Coated Copper Foils

Abstract

In this research we have studied the effect of surface-enhanced Raman scattering (SERS) of Rhodamine 6G (R6G) a highly fluorescent dye adsorbed on copper foils The impacts of surface roughness and graphene on SERS have been decoupled by utilizing atomic force microscopy (AFM) analysis and Raman measurement SERS is a high sensitivity technique for the detection of low concentration molecules and it is well known that surface roughness and coated material may benefit SERS effect since they both can result in the localized surface plasmon resonances (LSPRs) and thus an enhancement in Raman signal To ensure and decouple the enhancement in Raman signal caused by surface roughness and graphene respectively we prepared three samples a bare copper foil without annealing a foil experienced thermal treatment without growing graphene and a foil with graphene coated on it by using different recipes for chemical vapor deposition (CVD) process The surface roughness of three copper foils was measured by AFM in root mean square (RMS) value as 1 65 7 49 and 1 81 nm respectively In addition the lowest concentration of R6G to observe a R6G Raman signal (a k a the critical concentration) of each copper foil was measured to be 1 × 10?? 1 × 10?? and 1 × 10?? M respectively Combined with the results of AFM and Raman we can conclude that the sensitivity of R6G Raman signal is enhanced due to the roughness and graphene by a factor of 10 and 10? respectively

Date of Award	2017 Aug 18
Original language	English
Supervisor	Kuo-Hsing Kao (Supervisor)