Pulsed laser deposition (PLD) has become one of the most powerful methods to obtain a wide class of materials in the thin film form. The technique is based on the removal of material (ablation) from a target by means of a collimated beam of high energy laser (excimer, CO₂, Nd:Yag laser). The interaction of the laser beam with the target produces a higly oriented material stream (plume) ejected normally to the target surface that can be collected onto appropriate substrates positioned in front of the target. Such a stream (plume) consists of neutral and ionized atomic or molecular highly energetic species present in the target. Expansion of the laser generated plume is a complex pehenomenon depending on the collisions between particles in the plume and on plume-laser radiation interaction. Moreover if the expansion takes place in presence of a background gas strong variation of pressure and temperature occur in a short time interval so that a complete description of the process is still lacking. Research activity at the IPCF-CNR is mainly devoted to the growth by nanosecond pulsed laser ablation in an ambient gas of silver and gold nanoparticles (NPs). Several surface morphologies can be realized from isolated NP arrays up to percolated films. NP nucleate and grow in the expanding laser generated plasma propagating through the gas. Process parameters including laser wavelength, laser energy density, target to substrate distance, nature and pressure of the ambient gas affect the plasma expansion, thus asymptotic NP size and kinetic energy. The control of the deposition process favors the fine-tuning of NP aggregation, relevant to plasmonics to get optimized substrates for surface enhanced Raman spectroscopy (SERS). Detection of test molecules at concentration down to 10 nM was achieved. Substrates were used in several applicative studies: 1) SERS detection of and quantification of drugs of interest for Parkinson and epilepsy disease; 2) Sensor for the detection of volatile molecules (NPT); 3) Ad hoc substrates, polishing paper sheets, realization, decorated with silver and gold NPs removal and detection of very small quantities of organic dyes from the surface of works of art; 4) Functionalization of the substrates with chiral molecules for the realization of sensor chirality selective; 5) Functionalization of Silicon Nanowires for the realization of high sensitive SERS substrates, laser desorption ionization mass spectroscopy substrates and catalytic active SiNWs decorated with Au and Cu NPs;