A facile "one-pot" emulsion polymerization is reported to prepare surface-functionalized sub-micron spheres using novel amphiphilic comonomer as the reactive emulsifier. Specifically, amphiphilic 3-[2-(acryloyloxy)ethoxy]-3-oxopropyl(phenyl) phosphinic sodium (AEOPS) was used not only as a comonomer, but also as a good emulsifier for the polymerization due to the relatively long chain of amphiphilic structure. Nearly monodisperse polystyrene sub-micron spheres with tunable sizes and zeta potentials were obtained. The phosphinic group-functionalized surfaces were demonstrated by the use of these particles to remove heavy metal ions (such as Cd2+, Pb2+) from water with a high efficiency. (C) 2012 Elsevier Ltd. All rights reserved.