Antibacterial activity enhancement of silver deposited on TiO2 nanotube array

E. coli is an emerging cause of food borne and waterborne illnesses. The pathogenic serotypes produce a powerful toxin that may cause severe illness. Nanotechnology has significantly contributed to the lowering cost of waterborne E. coli bacteria elimination, using materials such as nano-scale Titanium dioxide (TiO₂). In this work, using anodization method, nanotube arrays of TiO₂ with 90-100 nm pore diameter were synthesized in an organic electrolyte containing fluoride ions. Deposition of Silver (Ag) on the large-surface TiO₂ nanotubes showed significant antibacterial activity on E. coli. A reductive doping was performed to increase the conductivity of the TiO₂ nanotubes, resulting in an improved uniformity of the silver deposition. Silver deposition was performed in a three-electrode electrodeposition cell using a cyanide-base silver electrolyte. Characterization of the fabricated structure, using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), confirmed the uniform deposition of silver onto the TiO₂ porous layer. Liquid medium test under light illumination followed by serial dilutions, resulted in perfect photo biocide efficiency of the immobilized Ag/TiO₂ against E. Coli.