Nanosilver-loaded metal–organic framework UiO-66 with strong fungicidal activity

Abstract

Molds are microorganisms capable of both contaminating different food matrices, leading to their organoleptic deterioration, and causing risks to humans due to the development of mycotoxins. To control this type of contamination process, silver nanoparticles are an effective alternative, particularly if they are applied through hosting in carriers that allow their gradual dosage. In this work, a green functionalization strategy of the metal–organic framework UiO-66 with dispersed cationic silver species was analyzed and optimized, obtaining a nanomaterial with a remarkable performance in fungal control. First, the MOF was obtained under an eco-sustainable protocol and, afterwards, the incorporation of silver with sodium citrate as additive was analyzed. The physicochemical properties of the obtained Ag/UiO-66 solids were analyzed through several characterization techniques such as XRD, FTIR, UV-DRS, TGA-SDTA, SEM-EDS, TEM and XPS. Then, the materials were evaluated in the growth control of the mold P. roqueforti isolated from contaminated food of industrial origin which was taken as a model microorganism. It is shown that Ag/UiO-66 has a strong antifungal action, reducing the growth of the colonies of P. roqueforti by a magnitude of 5 log after 72 h, and positioning it as a promising nanomaterial towards the control of fungal contamination.