A new, fast and convenient method for the preparation of gold-polyethylenglycol core-shell nanoparticles in water was described. The method pertains to the concomitant redox and polymerization reactions of the acrylic formulation induced by photochemically generated radicals from the photoinitiator, 2-hydroxy-2-methyl-1-phenyl-1-propanone. The nanoparticles were characterized by using Dynamic Light Scattering (DLS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). Homogenous core-shell structured nanoparticles obtained this way are expected to find important applications in bio-medical fields. (C) 2011 Elsevier Ltd. All rights reserved.