Comparison of Сore‐Shell Colloids of Silver and Gold Nanoparticles Capped by Arabinogalactan

Abstract Ecologically friendly green synthesis of plasmonic silver and gold nanoparticles with the help of polysaccharides acting both as reducing and capping agents became popular nowadays due to numerous applications of such nanobiocomposites. However, the formation of their core‐shell structures is not at all clear. The core‐shell structures of Au and Ag nanoparticles (NP) synthesized with the help of Siberian Larch arabinogalactan (ARB) is compared. The series of ARB@AgNP is studied with respect to metal content by light scattering (static, dynamic, and electrophoretic one), transmission electron microscopy, FT‐IR, and UV–vis. spectroscopy. The results are compared with those of ARB@AuNP series ( J. Phys. Chem C 2011, 115, 24627). Higher redox potential of Au 3+ ions is responsible for formation of thicker shells of oxidized and hydrolyzed ARB surrounding AuNPs and more negative zeta‐potentials of these colloids. Contrary to ARB@AgNP colloids with single spherical AgNP in the core, the ARB@AuNP colloids contained a fraction of AuNP dumbbells responsible for the depolarization of scattered light. The position of a slipping plane at which the zeta‐potentials are determined is attributed to the hydrodynamic radii of colloids ( R h ). Thus, the decrease of zeta‐potentials with the metal content is explained by the growth of R h .