Photochemical Synthesis of Gold Nanoparticles by Irradiation of Gold Chloride with the 2nd Harmonic of a Nd:YAG Laser

Abstract

A synthesis method was developed capable of obtaining pristine gold nanoparticles (AuNPs) using the lowest possible amount of auxiliary compounds. An aqueous solution of HAuCl 4 .3H 2 O was irradiated, in the absence of any stabilizing species, with the 532-nm radiation of a Nd:YAG laser. Spherical shaped AuNPs were produced by this method with sizes below 10 nm. The crystalline structures were stable for up to 28 days. A mechanism for this process is also proposed based on the initial cleavage of water molecules by the laser irradiation followed by the formation of hydrogen peroxide that reduces the gold species Au III. The resulting species of these reactions (H 2 and O 2) were identified by mass spectrometry. This new method suggests that laser irradiation is a feasible alternative to produce ready-to-use AuNPs, for drug delivery, diagnostics or bio-imaging.

Effect of pH and Irradiation Power in the Synthesis of Gold Nanoparticles by using Binahong (Anredera cordifolia) Leaves Extract

“…Synthesis of gold nanoparticles may follow many kinds of mechanism, such as templateassisted synthesis 1,2 , seed-mediated synthesis 3,4 , or high frequency energy-assisted synthesis 5,6 . Even though those mechanisms may yield nanoparticles with controlled morphology, however, those methods require many steps in the preparation and some of them may need high cost 7,8 .…”