Preparation and micropatterning of gold nanoparticles by femtosecond laser-induced optical breakdown

[Display omitted] •Gold nanoparticle preparation by irradiation of intense femtosecond laser pulses into 1-propanol-containing HAuCl4 aqueous solution was performed.•The reaction scheme is discussed based on the opticalbreak down of water.•In addition, micropatterning of gold nanoparticles via the optical breakdown was also demonstrated. We fabricated gold nanoparticles (NPs) via a femtosecond (fs) laser-induced cavitation bubbling. By introducing intense fs laser pulses into HAuCl4 aqueous solution containing 1-propanol, optical breakdown and the following cavitation bubble generation occurred at the focus through multiphoton absorption of water, resulting in the formation of gold nanoparticles (Au NPs). Intermediate species such as radicals and solvated electrons produced upon the bubbling contribute to gold ion reduction, while direct ionization of Au-chloride complex, photothermal decomposition and direct optical decomposition are excluded as possible mechanisms. Utilizing the fs laser-induced bubbling we demonstrate in-situ micropatterning of Au NPs on a substrate from the same HAuCl4 aqueous solution containing 1-propanol.