In this work, the basic theory and the applications of modified surfaces with nano-structured composites of Prussian Blue (PB) and Dendrimers of polyamidoamine (PAMAM), for the electrochemical detectors and electro-catalyze technologies, currently, represent some of the most promising approaches for the development of efficient and new materials for advanced electrochemical applications. As the PB interacts in supramolecular manner with PAMAM dendrimers in aqueous medium, across the hydrophobic zone of dendrimer, they form composites stables in solution with different generations of PAMAM. Dendrimers make the function of endoreceptors of PB forming composites of PB - PAMAM dendrimers, which can be used to construct PB films over gold surfaces, in covalent or electrostatic modification process, which can work as electro- catalysers to detect molecules with biologycal importance.