A facile electrodeposited fabrication of Ag, Co, and Ni nanoparticles for plasmonic properties and antibacterial activity

The electrochemical deposition method, a simple approach, has been used to prepare silver, cobalt, and nickel nanoparticles (NPs). The structural properties of the prepared samples were meticulously studied using X-ray diffraction (XRD), revealing good crystallinity in Ag, Co, and Ni NPs with face-centered cubic (FCC) structures for all metallic NPs. XRD also exhibited significant XRD peaks of alpha-Co(OH)2 phase with Co NPs and alpha-Ni(OH)2 phase with Ni NPs. As more metals beyond Au and Ag are being explored for nanoplasmonic applications-such as magneto plasmonics with Ni, Fe, and Co-a deeper conceptual understanding of the interactions between localized plasmon modes and interband transitions (IBTs) becomes crucial. The prepared metallic NPs have strong localized surface plasmonic resonance (LSPR) bands below 400 nm. This study investigated the interaction of LSPR with IBTs in Ag, Co, and Ni nanoparticles, which exhibit a strong coupling system. Moreover, the spectral localized IBTs for Co and Ni NPs lie in the UV region, which makes them excellent candidates for communication applications as nanoantennas. This finding has practical implications for the development of more efficient nanoantennas. An additional contribution of these NPs, the antibacterial activities of Ag, Co, and Ni NPs, were evaluated against three types of bacteria (Staphylococcus aureus, Salmonella typhi, and Pseudomonas aeruginosa). The inhibition zone varied in the range of (8-18 mm) with a variation of metallic NPs' concentration between 112.5 and 450 mu g/ml, indicating that the obtained nanoparticles can be improved for antibiotic applications.