Plasmonic detection of Cd2+ ions using surface-enhanced Raman scattering active core-shell nanocomposite

SERS spectra using (1) CV 10−4 M (2) CV+Au NPs (3) CV+SiO2@Au (4) CV+SiO2@Au+0.1 ppm Cd2+ (5) CV+SiO2@Au+1 ppm Cd2+ (6) CV+SiO2@Au+2 ppm Cd2+ (7) CV+SiO2@Au+5 ppm Cd2+ and (8) CV+SiO2@Au+10 ppm Cd2+ ions and visual detection of Cd2+ ions by speckled silica-gold core-shell solution.202