In this work, the single-photon emission of SiV-centers in HPHT-nanodiamonds positioned on the surface of silicon plate and gold film was investigated. Fluorescence spectra, saturation curves and fluorescence decay curves were measured for a number of SiV-emitters. A reduction in the fluorescence lifetime by ~20%, as well as a spectral shift and a decrease in the width of the zero-phonon line of SiV fluorescence were observed for most emitters. Analysis of the saturation curves revealed an increase in the emission rates by an average of 3 times, and up to 13 times for some particles. The wide variation is primarily associated with the orientation of the dipole moment of the SiV centers and the size of diamond particles, which are the key parameters regulating the coupling of the emitter with surface plasmons in the gold film.