PAMAM-CdS nanocomposites with their photoluminescence property were prepared in methanol solution and the ratio of Cd2+ and PAMAM was adjusted to investigate its effect on the optical property of the PAMAM-CdS nanocomposites. The formed PAMAM-CdS nanocomposites were adsorbed onto the melamine formaldehyde (MF) microspheres by electrostatic interaction to form microspheres with their photoluminescence property. Electrostatic layer-by-layer assembly of the PAMAM-CdS nanocomposites using poly(sodium 4-styrenesulfonate) (PSS) as the oppositely charged polyelectrolyte leading to MF microspheres with their photoluminescence intensity is reported. The formed composite microspheres can be applied in the fields such as biological assays. (c) 2007 Elsevier B.V. All rights reserved.