A One-Pot Fabrication of Chitosan Gel-Encapsulated Gold Nanoparticles Using Inkjet Mixing Technology

The one-pot synthesis of chitosan gel-encapsulated gold nanoparticles (AuNPs) was investigated by using an inkjet mixing system. Through the collision of microdroplets, AuNPs with an average diameter of 5.1 nm and a coefficient of variation of 0.19 were successfully synthesized via a reduction method. In the synthesis of chitosan capsules, it was found that the type of gelling agent influences the diameter and particle size distribution of the resulting capsules due to their reaction rates. Utilizing the advantages of the inkjet mixing system, the one-pot synthesis of chitosan gel-encapsulated AuNPs was successfully achieved. It was found that the time between the nucleation of AuNPs and gelation was critical for encapsulation. It was thus demonstrated that the potential of the inkjet mixing system can be expanded to the synthesis of various types of nanoscale products by designing the process and that the system can be a powerful tool to reveal the mechanism of nanoparticle synthesis by precisely tuning the conditions.