Multipurpose polymeric particles with core-shell morphology were prepared using acrylonitrile (AN) as core forming monomer, and methacrylic acid (MA) and acrylic acid (AAc) as shell monomers via microemulsion polymerization employing a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB). The synthesized particles are amenable for various applications, and demonstrated potential use: (1) as drug delivery devices in biomedical field, (2) in the removal of organic contaminants such as a herbicide (Paraquat) and an organic toxic species (4-nitrophenol (4-NP)) in environmental applications, and (3) as a template for the preparation of Cu catalyst and as a catalysis medium in the reduction of 4-nitrophenol to 4-aminophenol. The prepared p(AN-co-MA) and p(AN-co-AAc) particles were further chemically modified to make the particle more hydrophilic by conversion of nitrile groups to amidoxime groups. The amidoximated particles showed enhanced absorption capacity for organic and metal species and better catalytic activity. Furthermore, the particles were made magnetic field responsive for use in applications, i.e., removal of nanocomposites by an externally applied magnetic field after completing their assignments. (C) 2011 Elsevier B.V. All rights reserved.