Non-conventional techniques for physicochemical characterization of green synthesized silver nanoparticles

GONZÁLEZ FÁ, ALEJANDRO J.; DI NEZIO ,MARÍA S.; SPRINGER, VALERIA; PISTONESI, MARCELO F.; JUAN, ALFREDO

Congreso; 24th Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2018

Silver nanoparticles (AgNPs) have gained remarkable importance in the scientific/technological fields due to their unique optical and electronic properties, which are directly related to their intrinsic composition, sizes, shape and specific surface, among others. In this work green synthesized AgNPs, obtained by using carbohydrates as reducing and capping agents [1], were characterized by conventional techniques (TEM and DLS) and non-conventional techniques such as Surface Enhancement Raman spectroscopy (SERS), theoretical computational models based on the Density Functional Theory (DFT) and Capillary Electrophoresis (CE). Specifically, SERS and DFT were used to analyze the capping agents on the synthesized AgNPs. The experimentally obtained vibrational wavenumbers were comparable with those from the literature. Furthermore, D‐glucose and D‐gluconate adsorption geometries could be found on the silver surface according to the calculated normal modes and experimental calculations [2]. On the other hand, CE allowed to obtain valuable information about size distribution, zeta potential, electrophoretic mobility and stability of the obtained AgNPs in aqueous solution by a single electrophoretic run within a short analysis time (<12 min) [3]. Zeta potential values were estimated from the electrophoretic mobility through the Smoluchowski and Ohshima equations. Additionally, satisfactory relationship was observed between the electrophoretic mobility and the size of the negatively charged AgNPs. The obtained results were fully compared to those obtained by the conventional techniques, TEM and DLS. Hence, SERS, DFT and CE can be considered as emerging characterization techniques that may be used complementarily to the traditional techniques aiming to get additional information about the studied nanoparticles.References:1.A. J. González Fá, A. Juan, M.S. Di Nezio. Analytical Letters 50 (5) (2017) 877?888.2.A. Gonzalez Fá, I. Lopez Corral, R. Faccio, A. Juan, M.S. Di Nezio. Journal of Raman Spectroscopy. DOI: 10.1002/jrs.5466. 2018.3. A. González Fá, I. Cerutti, V. Springer, S. Girotti, M. S. Di Nezio, M.E. Centurión, M. F. Pistonesi. Chromatographia 80 (9) (2017) 1459-1466.