Production and photofragmentation of Au nanoparticles by 355 nm picosecond radiation

Fifth generation ethylendiamine-core poly(amidoamine) (PAMAM G5)-capped-gold-nanoparticles were prepared by ps laser ablation in water, by using the third harmonic of a ps Nd:YAG laser. Post-irradiation with the same wavelength causes efficient photofragmentation of the nanoparticles. We performed a comparison with analogous tests carried out with 532 nm ps pulses. We found that, while 532-nm-fragmentation is a 2-photon photoelectric process, 355-nm-fragmentation is linear.