Optical Response of Silver Nanoparticles Stabilized by Amines to LSPR based Sensors

Silver nanoparticles aminosilane capped were obtained as stable colloids. FTIR spectrum of these nanoparticles showed a strong interaction between amine groups and silver surface, being this property the source of the high stability of the colloidal particles. UV-visible spectrum showed the typical absorption owing the resonance of localized surface plasmon (LSPR). We show that the optical properties of the colloidal nanoparticles were influenced by medium conditions. A continuous shift of the maximum of absorption to longer wavelength was observed with the enhancement of Pb2+ and Cd2+concentrations. In this way, these nanoparticles can be used as LSPR sensors.