Present study aims at oats-based biosorbents for uranium sequestration. Nano-starch extracted from oats was acetylated using 10 % acetic anhydride of nano-starch. Comparative study of nano-starch and acetylated nano-starch for uranium removal was carried-out. Removal efficiencies observed was 97 % and 99 % for nano-starch and acetylated nano-starch under optimal conditions: initial U(VI) ion concentration = 30 ppb, reaction time = 30 min, temperature = 50 °C, and pH = 7.0. Optimum adsorbent dose of nano-starch was 0.75 g/25 mL and that of acetylated nano-starch was 1.00 g/25 mL. Structural and morphological analyses were carried-out using FTIR, XRD, and SEM-EDS. Nano-starch exhibited higher thermal stability with a Final Decomposition Temperature (FDT) of 620 °C. Adsorption data followed the Langmuir isotherm with adsorption capacity = 1.48 μg/g for 60 ppb initial concentration of U(VI) and pseudo-second-order kinetics (R