In the present work, we have employed a novel approach to induce the spin-filtering effects in ZGNRs by the adsorption of radicals on the ZGNR surface. With the adsorption of the radical on the ZGNR surface, we intend to break the spin degeneracy of ZGNRs due to the presence of unpaired electrons in the radicals. More importantly, our objective is to understand the interaction of radicals with the ZGNR surface and how this interaction will affect the spin-up and spin-down conductance, thus resulting in the spin-filtering efficiency. We choose trimethylenemethane (TMM) as the organic radical and hydrogen-passivated ZGNR having six carbon atoms along the width (6ZGNRH). TMM has been widely investigated both experimentally and theoretically. Similarly, 6ZGNRH can be synthesized experimentally with a bottom-up approach using a molecular precursor. Using first principle calculations, we have studied the interaction of the TMM radical (shown in Figure ) with the 6ZGNRH surface in the different configurations as shown in Figure . We begin with the description of the electronic structure, and magnetic and transport properties of TMM-adsorbed 6ZGNRH in comparison to the pristine 6ZGNRH. Our results demonstrate that the TMM is either chemisorbed or physisorbed on the 6ZGNRH surface depending on the adsorption site or configurations. Further, the spin-polarized electron transport is investigated by means of a DFT-based nonequilibrium Green's function (NEGF) approach.