In this work, the photokilling of Escherichia coli using a " one-pot " synthesized suspension of anatase crystallized nanoparticles is evaluated. Preliminary to the biological tests concerning the antibacterial efficiency, the fabricated suspension , using a derived sol-gel process in soft chemistry condition, is characterized. Structural properties of the nano-particles are investigated using Electronic Transmission Microscopy (TEM) equipped with Selected Area Electron Dif-fraction (SAED) probe and X-ray diffraction. The inorganic solid content was evaluated by Thermogravimetric Analysis (TGA). Photodegradation of Acid Orange 7 in aqueous solution was used as a probe to assess the photocatalytic activity of the elaborated suspension under UV irradiation. The photokilling of Escherichia coli in presence of hybrid TiO 2 nanoparticles suspended in aqueous liquid under UV irradiation is evaluated. Such TiO 2 nanoparticles suspension shows a strong bactericidal activity with the total destruction of bacteria after only one hour.