Femtosecond laser ablation of gold in aqueous biocompatible solutions to produce colloidal gold nanoparticles

Possibilities of the control of the size and size distribution of the colloidal gold particles produced by the 110-fs laser ablation from a gold plate in aqueous environment are studied. Compared to pure deionized water, significant reduction of the mean size and size dispersion of the produced particles was observed when the ablation was performed in aqueous solutions of cyclodextrins (CDs), while the efficiency of the size reduction depended on the concentration and type of the CD (α-CD, β-CD or γ-CD). In particular, ablation at 10 mM of β-CD led to a production of 2-2.4 nm particles with narrow size distribution of less than 1-1.5 FWHM, which were very stable under aerobic conditions without any protective agent present. In the UV-vis spectrum, the gold nanoparticles exhibited an absorption band at 520 nm due to the generation of plasmon resonances. The fabricated particles are of importance for biosensing applications.