Covalent immobilization of unmodified biological materials as proteins has been performed through a one-step and soft method. This process is based on a polyazidophenylene layer derived from the electroreduction of the parent salt 4-azidobenzenediazonium tetrafluoborate on gold substrates. The wavelength used (365 nm) for the photochemical grafting of a large variety of molecules as biomolecules is a key point to this nondestructive immobilization method. This simple process is also versatile and could be used for covalently binding a wide range of molecules such as polyethylene glycol moieties, for example. To validate this approach for biochip or microarray fabrication, a surface plasmon resonance imaging (SPRi) platform for immobilization of various antibody families was created by grafting G-protein through this process. This SPRi antibodies platform was tested with several consecutive cycles of antigen injections/regeneration steps without loss of activity.