Lanthanide cation like Eu3+ (europium Xe 4f66s0) doped functional nanomaterials of lanthanide oxides especially of gadolinium oxide (Gd2O3) as nanorods capped with monodispersed macromolecule (MDM) like polyvinylpyrrolidone (PVP) coated with natural biopolymers like proteins as human serum albumin (HSA) have been the most demanding and applied nanomaterials in areas of the biosensor, optical distinguisher, electronic fluoresces, upconversion, and surface plasmonic resonance (SPR) nanomaterials and others. The Gd3+ and Eu3+lanthanide cations with 4f7 and 4f3+ electrons in their 4f shells have been chosen for studies in this study. These cations have almost similar contraction activities with almost similar Fermi energy barriers.The closely placed electrons in their 4f shells have produced the thermodynamic and kinetic colloidal stability of the PVP@Gd2O3:Eu3+ and HSA@PVP@Gd2O3:Eu3+ functional nanomaterials due to stoichiometrically balanced oxidation potentials, hydrophobicity, and electrostatic dipoles. Various composite materials have been produced using natural fibers through adapted synthetic techniques, broadening their potential applications from automotive to biomedical sectors. Sisal, coconut, eucalyptus pulp, jute, bamboo, malva, hemp, banana, pineapple leaf, ramie bast, kenaf bast, flax, sugarcane fiber, date palm, and cotton are commonly utilized as natural reinforcements in polymer composites to enhance desired properties.