Very Stable EDTA-Stabilized Colloidal Silver Nanoparticles: The Role of Synthesis Parameters

Synthesis of silver nanoparticles (AgNPs) by use of well-tested reducing and capping agents has been studied widely to produce desired product qualities for many usages. However, the size, morphology, and stability of the colloidal AgNPs remain subject to intensive works. Here, we report on the stable EDTA capped AgNPs prepared by reducing Ag+ ions using ascorbic acid (AA) stabilized with ethylenediaminetetraacetate (EDTA) at mild conditions. The pH medium, the reducing and stabilizing agent concentrations, temperature, and reaction time were evaluated to give stable and monodispersed colloidal nanoparticles. The synthesis of colloidal AgNPs was successful at medium pH of 11 and a temperature of 30 degrees C. The peak of colloid localized surface plasmon resonance (LSPR) absorbance was observed at 396-398 nm, having a size distribution of about 17.9-23.8 nm, spherical shape, monodisperse, and zeta potential of -25.8 mV. The produced nanomaterials have good stability up to 24 weeks of storage time. The fabricated AgNPs show long-term stability, which is very promising for many potential applications.