A, FTIR spectrum of magnetic nanoparticles (MNPs). A peak at 634.71 cm-1 is due to Fe-O bond vibrations confirming MNPs synthesis. For OH groups, a peak is observed at 1634.80 cm-1. B, FTIR spectrum of conjugated ARG-MNPs. FeO peak (633.5 cm-1), N=C peak (2348.8 cm-1), and the overlapping peak of OH-NH (3568.7 cm-1) confirm successful conjugation of arginine with MNPs.