Electric potential distribution in selenium-containing hybrid polymer nanosystem as measured by means of atomic-force microscope (Kelvin probe method). AFM images of surface topography (left) and surface potential distribution (right). Scan size is 3.8 x3.8 microns. Hybrid nanosystem based on zero-valence selenium nanoparticles, stabilized by polyelectrolyte complex of sodium dodecyl sulfate (SDS) with the cation copolymer (CC) P(VP-C) of N-vinylpyrrolidone (VP) and N,N,N-triethyl-N-methacryloyloxyethylammonium iodide (C) was studied. The images were obtained by means of atomic-force microscope SmartSPM, AIST-NT. Kelvin probe image (right) displays irregular arrangement of complex charge along the surface: micelles edges with a 20 nm width, consist of positively charged copolymer fragments, but the inner part includes negatively charged SDS.