Fluorescent gold nanoparticles produced by femtosecond laser ablation with CTAB as a surfactant

Femtosecond laser ablation of gold in an aqueous solution of biologically compatible surfactant cetyl trimethylammonium bromide (CTAB) is shown to produce small nanoparticles with a narrow size distribution. The average size of the nanoparticles produced in 0.1 and 1 mM CTAB was found to the 5 ± 3 nm, compared with 10 ± 6 nm obtained in deionized water under the same ablation conditions. Moreover, they were also strongly fluorescent, with a broad emission band peaking at around 350 nm for optimized excitation at 290 nm. The emission was blue shifted compared to 410 nm peak for nanoparticles ablated in water.