▎ 摘　　要

Herein, we report an unprecedented bio-covalent functionalization of graphene with threonine through N-nu-cleophilic epoxide-ring opening followed by its embellishment with Co-spinel. Furthermore, the synthesized biomaterial, Co-spinel/Thr-G reduces nitro group efficiently towards drug sensing as electrochemical probe. The developed material is characterized by UV-vis, FTIR, Raman spectra, XRD, TEM, SEM with EDX, XPS, and CV. Under optimal conditions, the determination of metronidazole was recorded with DPV. The detection limit was found to be 3.9 nM in the linear range of 2.5 mu M-240 mu M at ambient reaction conditions.