A mica substrate was first coated with a positively charged layer of Polyl-L-Lysine by applying a drop of 0.1 wt.% aqueous solution for 1 min, and then rinsing. In the same manner a submonolayer of nanofibrils was deposited on the coated mica surface, from a 0.001 wt.% suspension in water. The fibrils were observed in a Nanoscope IIIa AFM (Picoforce SPM, Veeco, Santa Barbara, CA) in the tapping mode.