Distinct advantages of using sonochemical over laser ablation methods for a rapid-high quality gold nanoparticles production

Gold nanoparticles (AuNPs) have numerous usage in various applications, primarily in chemical and biological sensing. There are also various methods of producing AuNPs. However, in some of those methods, removing excess reagents, including ions or residual surfactants, can be difficult and time-consuming, while the functionalization of AuNPs with other types of molecules can only be achieved at lower efficacy. In this report, the AuNPs were produced using a rapid and solvent-free sonochemical and laser ablation methods. Morphology, structure and the colloidal stability of AuNPs produced by the two methods were analyzed and compared. Results have shown that the purity, homogeneity and crystallinity of AuNPs produced using the sonochemical technique showed better characteristics than those acquired by the laser ablation method. AuNPs also demonstrated smaller particle sizes (22 nm), smooth surfaces with higher colloidal stability (50.7 mV). The findings indicate that ultrasound irradiation power improves the crystalline properties of AuNPs and inhibits their agglomeration. The sonochemical approach can, therefore, be used to produce AuNPs with better physicochemical characteristics compared to laser ablation methods. (paper)