Fabrication and characterization of alloy nanodomes

Surface-enhanced Raman scattering (SERS) is an emerging analytical technique for characterization of biological and non-biological molecules and structures. Fabrication of tunable plasmonic nanostructures is the focal point for the design of novel SERS substrates due to their major contribution of electromagnetic enhancement to the SERS enhancement mechanism. In this thesis, a novel approach for the fabrication of Au-Ag, Au-Cu, and Ag-Cu alloy nanodomes having tunable plasmonic properties by changing of metal types and metal concentrations is demonstrated. First, convective-assembly method is used for deposition of the latex particles (1600 nm) on a glass slide uniformly to obtain template for the polydimethylsiloxane (PDMS) surface. After, PDMS is poured on the latex thin film to obtain nanovoids on the PDMS surface. The obtained nanovoids on PDMS are used as template for the fabrication of alloy nanodomes. The nanovoids are filled with the electrochemical co-deposition of two metals of interest to obtain alloy nanodomes having different metals and metals concentrations. The structural properties of all fabricated alloys are characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). SERS is used for the optical characterization of the fabricated alloy nanodomes. The abtained results demonstrate that, SERS performance of the alloy nanodomes is dependent both metal types and metals concentrations in the alloys. Key Words: SERS, Alloys, Bimetallic, Nanodomes, Electrochemical Coating