However, if the development of SAMs could be easily accomplished due to the compatibility of the chemisorption mechanism of organosulfur compounds with the TEMPO motif, grafting by diazonium reduction, which involves a radical mechanism, seems to be affected by the presence of the aminoxyl radical, as suggested by previous studies . Consequently, strategies revolving around in-situ formation of diazoniums in an acidic medium , post-functionalization of an organic layer or immobilization of TEMPO precursor species for subsequent regeneration on the modified surface , have been developed to yield functional layers. To prevent chemical reactions on a pre-formed layer that could lead to incomplete transformation yields, we directly immobilized TEMPO and to ensure optimal control over all parameters, we isolated the TEMPO-based diazonium salt instead of generating it in-situ. This approach ensured precise control of TEMPO's concentration and employed diazotization to adjust its redox state, thereby reducing aminoxyl radicals in the grafting solution.