Present work proposes green synthesis of reduced graphene oxide using lemon peel extract(vitamin-c) and its application as an electrochemical nonenzymatic human serum glucose sensor. Improved modified Hummer’s method was preferred for the preparation of graphene oxide. XRD, UV-Vis and XPS analysis revealed the successful reduction of GO using lemon peel extract. FESEM, FTIR and Raman spectroscopy supports the formation of rGO nanosheets. The proposed glucose sensor exhibit high sensitivity of 1402μA.cm−2.mM−1 (S/N=3) along with correlation coefficient of 0.9887 and low detection limit of 0.011μM.The sensor has detected glucose with RSD of 1.99% in human blood serum. The measured values are well agreed with the values obtained using professional glucose sensor used in hospitals.