Natural polysaccharides and microfluidics: A win-win combination towards the green and continuous production of long-term stable silver nanoparticles

Abstract

The present work combines the use of microfluidic reactors and green chemicals such as glucose and starch to achieve a continuous production of silver nanoparticles that have been successfully tested as excellent antibacterial agents against Escherichia coli. Those silver nanoparticles synthesized under continuous flow remained stable in terms of optical response, morphology and size distribution even after 48 months of storage at 24 °C without light protection. The best results in terms of colloidal stability were obtained after synthesizing those nanoparticles at 70 C in the presence of an excess of glucose when the continuous flow configuration was used to complete the reaction within 9 min. In contrast, analogous experiments carried out in batch conditions required a much longer period to achieve similar results but with much lower stability and a higher polydispersity, especially in the long-term storage range.