Amphiphilic poly(amidoamine) (PAMAM) dendrimers consisting of a hydrophilic dendrimer core and hydrophobic aromatic dansyl or 1-(naphthalenyl)-2phenyldiazene (NPD) shells have been synthesized. These amphiphilic dendrimers from the zero generation to the third generation self-assemble into vesicular aggregates in water. The self-assembly behavior of these dendrimers strongly depends on their generations. The generation dependence has been further investigated by an exploration of their electrochemical properties. For the PAMAM-NPD aggregates, the photoisomerization process leads to a change in the aggregate size.(c) 2005 Wiley Periodicals, Inc.