Synthesis, Characterization and Antibacterial Activity of Copper(II) Metal-Organic Nanocapsule

The antibacterial activity of a metal-organic nanocapsule [Cu2(dpa)2(bpy) 2]·4H2O (1), (H2dpa = diphenyl-2,2ꞌdicarboxylic acid and bpy = 2,2ꞌ bypyridine) was investigated against gram-positive and gram-negative bacterial strains. First, [Cu2(dpa)2(bpy)2]·4H2O was synthesized by both the reflux and sonochemical processes. Then, the obtained products were characterized by powder X-ray diffraction (PXRD), IR spectroscopy and scanning electron microscopy (SEM). Finally, their antibacterial performance was investigated by the agar well diffusion method. The results showed that the compound is active against S. aureus, whereas , it is inert against E. coli bacteria. The fact that bpy exhibited a high antibacterial performance against E. coli, while compound 1 samples were inert against E. coli bacteria shows that ligand release in metal-organic nanocapsule of 1 does not occur. It seems that the mechanism of compound 1 for its antibacterial activity is different from other reported compounds and is not attributed to Cu^2+ and ligand release from 1, because of its high chemical stability.