The study presents preparation and characterization of layer-by-layer assembled ultra-thin films. The versatility of layer-by-layer approach gives opportunity to prepare these ultra-thin films with different building blocks and investigate them using several spectroscopic techniques. The study focuses on characterization of layer-by- layer deposited ultra-thin polyelectrolyte layers on Si/SiO2 substrate by XPS, incorporation of Au and/or Ag nanoparticles in between polyelectrolyte layers using LbL deposition and investigation of their optical responses by UV-vis absorption spectroscopy and incorporation of Au ions into layer-by-layer assembled polyelectrolyte multilayers via ion- exchange and their subsequent reduction.