Antibacterial effect of metal-enzyme hybrid nanomaterials

The heterogeneous copper and cobalt catalysts (CoNPs-hybrid and CuNPs-hybrid) were synthesized using a protein-directed method to obtain catalytically active nanoparticles for wastewater disinfection, and fully characterized by ICP-OES, XRD, XPS, TEM and SEM analysis. CuNPs-hybrid demonstrated antibacterial capabilities, total removal of Enterococcus sp. (≈ 5-log reduction (LR)) in 120 min, at a concentration of 0.1 g/L, and efficient recyclability, by retaining this removal efficiency in the third cycle. Therefore, its high recyclability, low use of additional reagents, the sustainable nature of its synthesis, and high catalytic efficiency make this material a potentially attractive disinfectant. However, the opposite behavior was observed for the CoNPs-hybrid case, without disinfectant capabilities by its own. While with a Turnover Frequency (TOF) of the CoNPs-hybrid, of 1.84 h-1, and 99.9% degradation of pAP in 30 min, the analysis demonstrated the catalytic capacity of the CoNPs-hybrid. Therefore, the intensification of the process was performed adding peroxymonosulfate (PMS) and solar radiation. It was achieved a 2.5-LR disinfection rate in 120 min at a concentration of 0.05 g/L when activated by solar radiation, but it is still less than that obtained with external actors on an individual basis. X-ray diffraction showed that the catalyst composition is not stable throughout use, which is reflected in its low recyclability.