A substrate undergoing layer-by-layer (LbL) nanocoating. (A). Polyelectrolyte solution with a specified charge in a dipping container. The substrate is immersed in this solution for a predetermined time. (B). The coated substrate is placed in water to wash off the excess, unbound polyelectrolyte solution. (C). The washed, coated substrate is immersed in a polyelectrolyte solution of an opposite charge relative to the first solution. (D). A bilayer of the polycation and -anion is formed. The excess of the second polyelectrolyte (blue) is washed off to produce a substrate with a single bilayer of the polyelectrolytes as a nanocoating. The process is repeated for the desired amount of cycles.