Laser ablation synthesis in solution of metal nanoparticles for the easy functionalization and bioconjugation

Metal nanoparticles (MNP) obtained by laser ablation synthesis in liquid solution (LASiS) can be easily functionalized and bioconjugated. Stable MNP solutions can be obtained by LASiS in water or in organic solvents, without any ligands or chemicals. Hence, nanoparticles surface is usually free and functionalization with a wide range of organic- and bio-molecules occurs in one step, without place exchange reactions. Also the real time monitoring of the surface coverage is possible simply by UV-Vis spectroscopy.[1-3] We also found that size of AuNP obtained by LASiS can be further manipulated by chemical free laser techniques inspired by top down and bottom up approaches. Gold nanoparticles with average radii of 4.5 nm were obtained in this way, which allowed the sensing of AuNP bioconjugation with bovine serum albumin (BSA) down to 10:1 AuNP:BSA.[4] Finally, by exploiting the Mie and the Gans models for the calculation of the extinction cross section of spherical and spheroidal nanoparticles respectively, the size, the aggregation and the concentration of gold nanoparticles can be estimated in few minutes simply by fitting their UV-vis spectrum.[5