Synthesis of conductive Cu-core / Ag-subshell / polyaniline-shell nanocomposites and their antimicrobial activity

Abstract

Core shell technique was used to synthesize conductive Cu-core / Ag-subshell / polyaniline-shell nanocomposites (NCs) and evaluating their antimicrobial activities. This was achieved through two stages, firstly different Cu/Ag core shell nanoparticles (Cu/Ag NPs) were prepared (C/A1, C/A3, C/A5), using electroless plating technique by reduction of AgNO3 in alcoholic dispersion of Cu NPs at three different weight ratios of AgNO3: Cu. Secondly, the prepared Cu/Ag NPs were further coated with polyaniline (PANI) by oxidative polymerization of aniline in their aqueous dispersions to form PANI/(Cu/Ag) NCs (NC1, NC3, NC5). XRD patterns of Cu/Ag NPs revealed their bimetallic crystalline structure. SEM micrographs and EDAX data proved formation of Ag thin shell on the surface of Cu core. The concentration of this silvery layer increased from ≈ 38% (C/A1) to 68% (C/A5). SEM and EDAX data of NCs, showed that PANI film wrapped 60% to 63% of Cu/Ag NPs surface that Cu nearly diminished. The synthesized NCs possessed good electrical conductivity that increased with Ag content from 0.52 S/m (NC1) to13 (NC5) S/m. Good antimicrobial activities (antibacterial and antifungal), of Cu/Ag NPs and their NCs were obtained. Such good conductivity and antimicrobial activity nominate the NCs to be applied in electronic and biotechnical fields.