The escalating global energy demand necessitates enhanced oil recovery methods, particularly offshore. Biological nanotechnology offers sustainable, environment-friendly, and cost-effective alternatives to synthetic chemicals. This study explored the synthesis of polysaccharide-based nanoparticles (PNPs) from Corchorus olitorius leaves using a weak acid-assisted ultrasonic method and their application as nanocomposites for oil recovery. The PNPs were characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, zeta potential, and