ZnO nanowire-immobilized paper matrices for visible light-induced antibacterial activity against Escherichia coli

Paper matrices showing antibacterial activity were prepared by immobilizing ZnO nanowires (NWs) of diameter ca. 130-500 nm and length up to 2.5 mu m on the surface of cellulose fibers by a single-step hydrothermal method. The antibacterial activity of the paper matrices has been investigated versus the visible light exposure time and ZnO contents (2.0 to 18.0 wt%). A complete inhibition of E. coli growth (i.e. 99.99%) was observed with the ZnO-immobilized paper matrices for 6 to 9 h exposure. A possible growth mechanism for the ZnO NW growth on the surface of the cellulose fibers has been proposed. The immobilization of ZnO NWs in paper matrices was characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoluminescence spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy.