Titanium dioxide nanoparticle doped with Europium ions Eu3+ was synthesis by performing of sol gel technique, the UV-Visible spectroscopy and fluorescence spectroscopy were used to investigate the spectroscopic properties of prepared doped sample. Two peaks at wavelength around 590nm and 612nm are recorded in fluorescence spectrum (wavelength of excitation light source equal to 390nm). The UV-Visible and fluorescence spectra are analyzed to determined peak emission cross-section σem. Depending on the suitable value of σem, it could strongly suggest to use Eu:TiO2 as optical material for laser action.

A new contrast agent in medical imaging discovered and developed since 10 years ago and it's under study until this moment because the classic contrast agents impose earnest limitations on medical imaging abilities such as the short imaging time, poor contrast X-ray images for obese patients (over weighted patients) and real side effects renal problems and toxicity problems. The new contrast agent is the Gold Nanoparticles (GNP) may overcome these restrictions due to its properties where the (GNP) bio distribution is higher than tri-iodobenzene compounds. also, bone /tissue interference is more clear and obvious than tri-iodobenzene compounds and in general nanoparticles clear the blood slowly than classic contrast agents which permit for longer imaging time and all of that leads to enhancing the X-ray diagnostic. Gold Nanoparticles were injected intraperitoneally into mice then images were taken by conventional X-RAY unit. Tumors were seen clearly.