Convenient Photochemical Synthesis of Silver-Polyaminocyclodextrin Nanocomposites: The Role of the Light Source from a Mechanistic Viewpoint

An investigation on the light-driven reduction of the [Ag(NH3)2]+complex in the presence of polyaminocyclodextrins was carried out, in order to clarify the mechanism of the process. The role of the organic auxiliary as both the sacrificial reductant and the capping agent was positively assessed. Moreover, particular attention was paid to the role of the irradiation source. Experimental results indicate that a complex mechanism is involved in the formation of the nanocomposite, with a primary photoinduced single-electron-transfer process promoted by irradiation with green light, followed by a secondary chemical reduction process activated by NIR. Representative composites were characterized by means of FTIR, TEM and SAED techniques. The light-driven approach proposed here appears an appealing “green”, bio-friendly method for the synthesis of stable nanosized silver composites, in view of possible applications as antimicrobial agents.