Design e sintesi di nuove sonde luminescenti per il "targeting" dell'avidina

Recent studies on the use of bio-conjugating organometallic probes report on the possibility to use biotinylated-derivatives to selectively coordinate to a specific protein, avidin. In the present thesis, the synthesis of four new bifunctional ligands is described. The ligands contain both a pyridine triazolic unit able to coordinate a transition metal, and a biotin fragment able to bond avidin: the two functionalities are linked together by an appropriate aromatic linker (amide or ester). The obtained ligands were then employed to form luminescent Ir(III) complexes, that have been fully characterized also by a photophysical point of view both in organic and in aqueous solvent. Therefore, titrations of solutions of avidin with aqueous solutions of Ir(III)-complexes have been performed in order to estimate the luminescence variations of the complexes in the presence or in the absence of bio-conjugation.

Elettrodeposizione di catalizzatori a base di Rh su schiume e fibre metalliche di FeCrAlloy per la produzione di syngas

The preparation of structured catalysts active in the catalytic partial oxidation of methane to syngas, was performed by electrosynthesis of hydroxides on FeCrAlloy foams and fibers. Rh/Mg/Al hydrotalcite-type compounds were prepared by co-precipitation of metallic cations on the support and successive calcination. Electrochemical reactions have been studied during the electrodeposition by linear sweep voltammetry. The experiments were performed at supports immersed in KNO3, KCl, Mg2+ and Al3+ aqueous solutions, starting by different precursors (nitrate and chlorides salts) and modifying the Mg/A ratio. Rh/Mg/Al hydrotalcite-type compounds were deposited on metal foams by applying a -1.2V vs SCE potential for 2000s with a nitrate solution of 0.06M total metal concentration. Firstly it was studied the effect of Mg on the coating propierties, modifying the Rh/Mg/Al atomic ratio (5/70/25, 5/50/45, 5/25/70 e 5/0/95). Then the effect of the amount of Rh was later investigated in the sample with the largest Mg content (Rh/Mg/Al = 5/70/25 and 2/70/28).The results showed that magnesium allowed obtaining the most homogeneous and well adherent coatings, wherein rhodium was well dispersed. The sample with the Rh/Mg /Al ratio equal to5/70/25 showed the best catalytic performances. Decreasing the Rh content, the properties of the coating were not modified, but the catalytic activity was lower, due to a not enough number of active sites to convert the methane. The work on metal fibers focused on the effect of precursor concentration, keeping constant composition, potential and synthesis time at the values of Rh/Mg/Al =5/70/25, -1.2V vs SCE and 1000s. However fibers geometry did not allow to obtain a high quality coating, even if results were quite promising.