Inorganic compounds with nanometer dimensions are different from the bulk materials because of having some specific features about their structures, like electronic confinement effects. These compounds are called "nanoparticles". Since the 1970s scientists have investigated nanoparticles to identify and determine their properties. In the beginning, studies centered on optic and electronic devices, however, researches now focus on bioassays. This short view outcomes recent applications in bioassays with nanoparticles.