Functionalized core-shell Ag@TiO2 nanoparticles for enhanced Raman spectroscopy: a sensitive detection method for Cu(ii) ions.

This paper demonstrates the use of surface plasmon resonance of core-shell Ag@TiO2 particles in SHINERS experiments. A copper(ii) complex grafted onto Ag@TiO2 surface was probed by Raman spectroscopy using resonance excitation profiles vs. excitation wavelengths (514, 633 and 785 nm) to tune the Raman signals. Enhancement factors of the SHINERS assembly have been estimated and compared to the SERS effect of unmodified silver NPs colloidal dispersions. Finally, the grafting of the copper(ii) complex onto Ag@TiO2 was advantageously compared to the grafting onto Ag@SiO2 shell.