In conclusion, we report the electronic and transport properties of organic radical-deposited ZGNRs. After describing the AFM spin configuration and spin-degenerate transmission spectra of pristine ZGNRs, we proposed the possibility of breaking the spin symmetry of edge atoms of pristine ZGNRs by adsorption of TMM radical on the ZGNRs surface. We demonstrated that the TMM is either chemisorbed or physisorbed on the 6ZGNRH surface depending on the adsorption site. The TMM is chemisorbed when the three carbon atoms of -CH 2 groups of TMM are deposited on the carbon atoms of 6ZGNRH (top site). The spin transfer from TMM to 6ZGNRH due to the chemisorption of TMM induces a magnetic moment of 1.853 µ B on the 6ZGNRH. It breaks the spin symmetry of edge atoms of 6ZGNRH resulting in -0.250 µ B and 0.292 µ B average edge magnetic moment of upper and lower edge atoms respectively. Further, the spin-resolved transport properties of TMM adsorbed 6ZGNRH show the transmission dip due to interference between localized states of TMM and 6ZGNRH states. Thus, the broken spin symmetry of edge carbon atoms of ZGNRs and the presence of spin-resolved DQI features near the Fermi level, result in 59.9% spin filtering efficiency at the Fermi level in the T6ZN-G4 configuration. The SF E can be further enhanced up to 91.5% under the application of 1.0 V bias voltage.