Antimicrobial activities of three Cu-based coordination polymers

The present work reports the synthesis and characterization of three Cu-based coordination polymers (CPs): [Cu (NO3)2(DTP)2(H2O)2]n (Cu-1 ), (DTP = 3,5-di(1,2,4-triazol-1-yl)pyridine), [Cu(ClO4)2(DTP)2]n(Cu-2), and [Cu (SO4)(DTP)(H2O)]n(Cu-3). The Cu-CPs were characterized by single-crystal X-ray diffraction analysis, powder Xray diffraction analysis, elemental analysis, infrared spectroscopy, thermogravimetric analyses, and N2 adsorption. The anti-bacterial and anti-fungal activities of the CPs were investigated experimentally, where the materials exhibited significant inhibition ability towards three bacteria ( Escherichia coli, Xanthomonas campestris, and Xanthomonas oryzae) and four fungi ( Physalospora piricola, Fusarium oxysporum, Alternaria alternata, and Glomerella ciningulaia). Fluorescence microscopy, agarose gel electrophoresis for the three bacteria, and scanning electron microscopy for Alternaria alternata were further evaluated. The results suggested a slow release of Cu2+ from Cu-1 would damage the cell membrane, DNA, and mycelium of the pathogenic microorganisms. Cu-1 barely affected the growth of Bacillus subtilis. This work constitutes the first study to demonstrate the antimicrobial properties of Cu-CPs against Xanthomonas campestris, Xanthomonas oryzae, Physalospora piricola, Alternaria alternata, and Glomerella ciningulaia.