Electrodeposited chrome/silver nanoparticle (Cr/AgNPs) composite coatings: Characterization and antibacterial activity

Composite coatings consisting of chrome and silver nanoparticles (Cr/AgNPs) with antibacterial activity were formed via electrodeposition and characterized using X-Ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The AgNPs were uniformly distributed inside and on the surfaces of the coatings, which was corroborated using SEM-EDS. The concentration of the AgNPs in the coatings varied as a function of the concentration of AgNPs in the electrolytic bath. The antibacterial activity of the Cr/AgNPs coatings was evaluated against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria using two well-established microbiological techniques: a bacterial growth inhibition test and the most probable number method. The results showed effective growth inhibitions of 99.98% and 99.92% for Escherichia coli and Staphylococcus aureus, respectively, after 60 min of direct contact between the Cr/AgNP coating (5.8 mg cm−3) and the bacteria inoculum.