Structures with US, PbS, ZnS quantum dots (QDs) produced using the Langmuir-Blodgett technique were investigated by infrared (IR), Raman and ultra-violet-visible (UV-Vis) spectroscopies. The QDs size derived from the analysis of UV-Vis spectra and high-resolution transmission electron microscopy images amounts to 2-6 nm. The IR and Raman spectra reveal longitudinal optical phonons localised in QDs and surface vibrational modes. The frequency positions of the surface optical vibrational modes are adequately described taking into account confinement of fundamental optical phonons in the QDs.