The present invention is related to a method for immobilising a biomolecule on a surface by generating and maintaining an atmospheric pressure plasma, the method comprising the steps of: introducing a sample in the space between two electrodes, a mixed atmosphere being present between the electrodes, applying an alternating voltage to the electrodes for generating and maintaining a plasma in the volumetric space between the electrodes, characterized in that the mixed atmosphere comprises an inert gas or nitrogen, an aerosol comprising a reactive precursor and an aerosol comprising a biomolecule, the reactive precursor and biomolecule being deposited and immobilized during the depositing step.