A biocompatible substrate having an electron donating surface with metal particles comprising palladium on said surface is disclosed. The substrate comprising an electron donating surface with metal particles on said surface, wherein each metal particle comprises palladium and at least one metal selected from the group consisting of gold, ruthenium, rhodium, osmium, iridium, and platinum, wherein the amount of said metal particles on said surface is from 0.001 to 8 µg/cm2. wherein said metal particles have an average size of 10-10000 Å, wherein said particles are distributed particles on said surface from a colloidal suspension of the particles and wherein the metal particles do not form a covering layer.