Green route synthesis of alpinia calcarata functionalized gold nanoparticles for nonlinear optical applications

Gold nanoparticles are synthesized from alpinia calcarata extract. The synthesized nanoparticles are considered for their structural, morphological and nonlinear optical properties. Powder X-ray diffraction analysis revealed the structural purity of the prepared samples. FTIR confirmed the presence of biomolecules involved in the reduction and stabilization process. UV–visible spectroscopic studies confirmed the Surface Plasmon Resonance of the prepared nanoparticle. HRTEM exposed the spherical shape morphology of the prepared gold nanoparticles. Zeta potential analysis inferred the stabilization of gold nanoparticles. The synthesised gold nanoparticles are found to be poly-dispersed with an average size of 15 nm. The studies suggest that the glucose and its complex in the alpinia calcarata extract are responsible for the reduction nanoparticles, whereas proteins act as capping agents around the nanoparticles. The Z-scan studies discovered the nonlinear optical behaviour and thus measured its parameters.