Encapsulation of snail slime in metal organic framework ZIF-8

Metal Organic Frameworks (MOFs) are hybrid polymeric synthetic materials widely explored recently, consisting of a metal center and organic linkers. This thesis describes the possibility of encapsulation of snail slime, called Madonita (Mad), in the porosities of a type of MOF called ZIF-8 (Zeolitic Imidazolate Framework), via a one-pot synthetic path, performed at room temperature. The system Mad@ZIF-8 was synthesized tuning the quantity of Mad and the concentrations of the precursors of ZIF-8’s namely Zn(OAc)2∙2H2O and the organic linker 2-HmIM and their molar ratio. In this way it was possible to obtain the morphology with the highest surface area and porosity, called sodalite. The ZIF-8’s structure and the presence of encapsulated Mad were confirmed by means of several analytical and spectroscopic techniques. Successively, the encapsulation efficiency was also studied using the tagging method with two different fluorophores: NHS-Rhodamine and Fluorescein isothiocyanate isomer I. With this aim, the Mad@ZIF-8 system has been compared with Mad-ON-ZIF8, a sample with the snail slime solely absorbed on the surface of ZIF-8. Both samples, after being tagged, have been analyzed in different ways for the purpose of studying the differences between them before and after the treatment with sodium dodecyl sulphate (SDS), which removes only the proteins adsorbed on the surface of ZIF-8, in order to quantify the percentage of encapsulation of Mad inside porosities of ZIF-8. This thesis will also show the studies carried out to explore the possibility of using cellulose as a support for ZIF-8, for a possible application in the field of water remediation. The reaction conditions were tuned to obtain workable sheets and the amount of Zinc deposited upon the cellulose fibers was evaluated by ICP analyses. Moreover, tests performed on different bacterial strains clearly demonstrated the effective role of ZIF-8 towards the inhibition of bacterial growth.