Tailored Rh surface facilitates, enhancement of Raman scattering in trimetallic AuPt core/Rh shell composites: Experimental and theoretical evidences

•Trimetallic AuPt core/Rh shell colloidal nanocomposites have been synthesized.•Adsorption behavior of 7-AI and L-Cys on the surface has been described.•–N1 site of 7-AI, –S1 site of L-Cys adsorption provides the most stable by DFT.•Formation of core–shell has been proposed from UV–vis, HR-TEM and SERS analysis.•Understanding of adsorption of probe molecules on metal surface has been proved.

We present a detailed analysis of surface-enhanced Raman scattering of 7-azaindole and L-cysteine adsorbed on a tailored Rh surface by using experimental and density functional theoretical (DFT) calculations. DFT with the B3LYP/Lanl2DZ basis set was used for the optimization of the ground state geometries and simulation of the surface-enhanced Raman spectrum of probe molecules adsorbed on Rh6 cluster. 7-azaindole and L-cysteine adsorption at the shell interface was ascertained from first-principles. In addition, characterization of synthesized trimetallic AuPt core/Rh shell colloidal nanocomposites has been analyzed by UV–visible spectroscopy, high-resolution transmission and scanning electron microscopy, selected area electron diffraction pattern analysis, energy-dispersive X-ray spectroscopy, atomic force, confocal Raman microscopy, FT-Raman and surface-enhanced Raman spectroscopic analysis. This analysis serves as the first step in gaining an accurate understanding of specific interactions at the interface of organic and biomolecules and to gain knowledge on the surface composition of trimetallic Au/Pt/Rh colloidal nanocomposites.

Graphical abstractThis investigation serves as first-step in gaining the understanding of specific interactions at the interface of probe molecules and to gain knowledge on the surface-composition.Figure optionsDownload full-size imageDownload as PowerPoint slide