Surface Enhanced Raman Scattering Studies of Silver-gold Normal and Inverted Core-shell Nanostructures on their Efficiency of Detecting Molecules

The intense significance of biological molecules in our everyday lives has prompted the research into the analysis, identification and quantification of these molecules. Recently, surface-enhanced Raman scattering (SERS) study is identified as one of the effective techniques to detect and quantify such bio-molecules, as these processes are indispensable in order to use them in biological applications. Such detection of molecules by SERS depends predominantly upon SERS active metal substrates such as the typical colloidal silver-gold nanostructures. However, identifying and fabricating suitable metal nanostructures for detecting such biomolecules is an essential need to implement them for practical applications particularly in extensive physiological environments. Herein, we report the synthesis of Ag-Au normal and inverted core-shell nanostructures and investigation of their plasmonic properties to detect drug molecules such as methylene blue and methyl orange using the surface enhanced Raman scattering technique. Our investigation promises for an easy reproduction of biocompatible silver-gold bimetallic core-shell nanostructures that possess excellent chemical stability which can be ideal candidates for a wide range of biomedical applications.