l-Glutamic acid functionalized silver nanoparticles and its nonlinear optical applications

l -Glutamic acid functionalized silver (Glu-Ag) nanoparticles (NPs) were synthesized in the aqueous medium and in a sol–gel matrix. Both samples showed different UV/Vis, zeta potential, TEM and SEM profiles. Surface enhanced raman spectra of the colloidal NPs reveal that the amino moiety of Glu is bound on the Ag surface with the charged carboxylate group pointing outwards. In contrast, in the sol–gel media, the attachment of Glu to the Ag NP surface was through the carboxylate group. Intensity-dependent nonlinear optical absorption measured using the open aperture Z-scan technique revealed that the aqueous solution of Glu-Ag is an efficient optical limiter.