Laser synthesis emerges as a suitable technique to produce ligand-free nanoparticles, alloys and functionalized nanomaterials for catalysis, imaging, biomedicine, energy and environmental applications. In the last decade, laser ablation and nanoparticle generation in liquids has proven to be a unique and efficient technique to generate, excite, fragment and conjugate a large variety of nanostructures in a scalable and clean way. In this work, we give an overview on the fundamentals of pulsed laser synthesis of nanocolloids and new information about its scalability towards selected applications. Biomedicine, catalysis and sensing are the application areas mainly discussed in this review, highlighting advantages of laser-synthesized nanoparticles for these types of applications and, once partially resolved, the limitations to the technique for large-scale applications.

The synthesis by pulsed laser ablation and the characterization of both the surface nanostructure and the optical properties of noble metal nanoparticle-based substrates used in Surface Enhanced Raman Spectroscopy are discussed with reference to application in the detection of anti-epileptic drugs. Results on two representative drugs, namely Carbamazepine and Perampanel, are critically addressed.

The structural and elastic properties of a thin gold film alloyed with Cu and Ni have been studied by surface Brillouin scattering, x-ray reflectivity and low angle x-ray diffraction. The role of guided (Sezawa) acoustic modes to determine precise values of the elastic constants has been ascertained. Although weak, the hardening effect of alloying elements has been clearly detected.

Pyrolytic graphite has been irradiated with high-energy density laser pulses ͑248 nm wavelength, 20 ns duration, and up to 250 J/cm 2 energy density͒. Craters with depth up to 5 m have been obtained by irradiating with a single pulse and the bottom of the craters has been analyzed with many techniques to investigate the possible morphological and structural modifications induced in the irradiated material where temperature and pressure fields, appropriate to the graphite-diamond phase transition, may be achieved. Melting of the surface layers of the irradiated graphite was realized, as established with scanning electron microscopy, while the estimated and measured pressure attained a maximum value on the order of 2.5 GPa. The temperature profile depends on the depth below the irradiated surface and the observed structural modifications are associated with different depths. Just below an ordered sp 2 hybridized nanocrystalline graphite surface layer, a disordered graphitic layer was formed, within which diamond particles with spheroidal geometry are embedded.