Preparation of corn starch by pullulanase to obtain starch nanoparticles (StNPs) with high yield and short duration was considered as the best way for green industry of StNPs as compared with other preparation procedures. Morphology investigation of prepared StNPs by scanning electron microscope (SEM), particle size by Dynamic light scattering (DLC) and Transmission electron microscope (TEM),group changing by Fourier transforms infrared spectroscopy (FTIR) and crystallinity by X-ray diffraction (XRD).Modification of StNPs via crosslinking with citric acid to obtain StNPs citrate. A novel adsorbent of obtained StNPs citrate was examined for dye-removing from aqueous solutions. Crystal violet dye was remediated with StNPs citrate to investigate the adsorption efficiency. Batch experiments were carried to study the optimum pH, contact time, adsorbent dose, initial dye concentration and temperature to assess the kinetic from isotherm of adsorption. The experimental data were best fitted to pseudo second order and Langmuir isotherms. Thermodynamic functions such as free Gibbs energy (∆G°), enthalpy (∆H°) and entropy (∆S°) of the sorption were calculated, thus indicated spontaneous and endothermic adsorption process.