A method for depositing functional groups on a surface of an object, and to the object treated as such, by generating and maintaining a plasma, bringing the object surface close to or in a space between the plasma electrodes, an atmosphere being present between the two electrodes, and depositing a plurality of functional groups on at least part of the surface of the object, wherein the atmosphere between the two electrodes comprises a multi-functional hyperbranched compound which is a polymer based on ABm type monomers, or a derivative of such polymer, wherein m is at least 2, A and B have reactive functional groups selected such that group A is reacted at least m times with group B, and the hyperbranched compound has a degree of branching (DB) in the range of 10.0-99.9%.