We report the results of study of gold and silicon nanoparticles as contrasting agents for diffuse optical spectroscopy (DOS). Optical properties of the nanoparticles suspensions and model objects were obtained from spectrophotometric measurements in the wavelength range of 500-1100 nm. The DOS measurements were performed with a liquid phantom consisting of water, lipofundin and ink mixture providing optical properties of the solution close to those of biotissue. The phantom contained an inclusion filled with lipofundin and aqueous suspension of gold nanoparticles (GNPs) which were characterized by strong absorption in the red and near infrared spectral range. The inclusion contrast in the obtained DOS images was estimated, which allowed to consider the selected GNPs as potentially perspective contrast agents for DOS applications.