Amino functionalized thin films prepared from Gabriel synthesis applied on electrografted diazonium salts

A new diazonium salt bearing an aliphatic primary amine protected with a phthalimide group has been synthesized and isolated from the reaction of the corresponding aniline derivative with NOBF4 in acetonitrile. Electrochemical grafting of this compound in potentiodynamic conditions on vitreous carbon or on gold form thick, stable, adherent and insulating polyphenylene-like films on the electrode surface. Treatment with hydrazine of these polymers cleaves the imide functions to release amine groups prone to subsequent immobilization of molecules, biomolecules or particles via a covalent amide linkage. That primer polyphenylene-like layer establishes a good electrical communication between the surface of the electrode and the immobilized probes.