Selective adsorption activities toward organic dyes and antibacterial performance of silver-based coordination polymers

Two silver-based coordination polymers, [Ag2(bpy)2(cbda)] (BUC-51) and [Ag3(bpy)3(cpda)]·(NO3)·9H2O (BUC-52), have been successfully prepared by slow evaporation at room temperature. These coordination polymers exhibited good adsorptive performances toward series organic dyes with sulfonic groups, which could be ascribed to the AgcdotsO interaction between the silver(I) atoms in CPs and the oxygen atoms from sulfonic groups attached to organic dyes. Both BUC-51 and BUC-52 favoured slow release of Ag+ ions resulting into outstanding long-term antibacterial abilities toward Gram-negative bacteria, Escherichia coli (E. coli), which was tested by a minimal inhibition concentration (MIC) benchmark and an inhibition zone testing method. Both scanning electron microscope (SEM) and transmission electron microscope (TEM) images demonstrated that these two Ag-based coordination polymers could destroy the bacterial membrane and further cause death. Additionally, the excellent stability in common solvents and good optical stability under UV-visible light facilitated their adsorptive and antibacterial applications.