Abstract A nanoparticles chelating solution was synthesized by copolymerization of acrylonitrile (AN) and methacrylic acid (MAA) by radiation induced polymerization technique using 17 kGy irradiation doses. A high copolymer yield was obtained by using 80/20% of AN/MAA and comonomer concentration of 50% (w/w) at a dose rate of 2.58 KGy/h. The resultant cyano group (–CN) of nano-poly(AN/MAA) was converted by chemical modification using hydroxylamine (NH2–OH) to an amidoxime group [–C(=NOH)NH2], which was then confirmed by Fourier transform infrared spectroscopy (FTIR). The physico-chemical properties of poly(AN/MAA) and amidoximated poly(AN/MAA) nanoparticles were studied by FTIR, transmission electron microscopy (TEM), dynamic light scattering (DLS) and thermal gravimetric analysis (TGA). The morphological analysis by TEM and DLS showed a spherical and uniform size of the amidoximated poly(AN/MAA) nanoparticles. TGA results indicated that the thermal stability of poly(AN/MAA) increased by the amidoximation process. The surface decontamination due to uranium was also investigated by the prepared chelating nanoparticles solution. A high purity germanium detector (HPGe) was used as a surface contamination detection tool. The results showed the presence of peaks at different energies, namely, 186.2 keV for Ra-226 (U-238) and 143.76 keV, 163.35 keV and 205.31 for U-235 before the decontamination process. The disappearance of these peaks after decontamination confirmed the applicability and efficiency of the nanoparticles solution in uranium surface decontamination.