Preparation of hybrid particles of Ag nanoparticles and eggshell calcium carbonate and their antimicrobial efficiency against beef-extracted bacteria

Abstract

In this study, hybrid particles of AgNPs-loaded eggshell calcium carbonate (AgNPs/eCaCO 3 ) were prepared by co-precipitating the eggshell in the presence of freshly prepared AgNPs with a particle size of 10–30 nm. The hybrid particles were comparatively precipitated at 25°C and 35°C using poly (sodium 4-styrenesulfonate) as a polyelectrolyte. The AgNPs/eCaCO 3 particles prepared at 25°C had a spherical morphology with a mean diameter of 3.56 µm, and Brunauer–Emmett–Teller (BET) surface area of 85.08 m 2 g −1 . On the other hand, the particles prepared at 35°C had a broader size distribution with a mean diameter of 3.19 µm, and a BET surface area of 79.25 m 2 g −1 . AgNPs-loaded commercial calcium carbonate particles (AgNPs/CaCO 3 ) comparatively prepared at 35°C were perfectly spherical with a mean diameter of 5.61 µm. At preparing temperature of 25°C, the hybrid particles contain AgNPs of 0.78 wt% for AgNPs/eCaCO 3 and 3.20 wt% for AgNPs/CaCO 3 . The AgNPs/eCaCO 3 and AgNPs/CaCO 3 particles exhibited the same efficiency against bacteria extracted from beef with an average inhibition zone diameter of 7–10 mm according to the modified Kirby–Bauer disc diffusion assay depending on their concentration and beef source. Freshly prepared silver colloids showed comparatively poorer antimicrobial efficiency.