▎ 摘　　要

Few layered graphene nanosheets were successfully doped with nitrogen through microwave irradiation and thoroughly characterized by using electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The electrochemical efficiency of N-doped graphene toward enzyme-free detection of uric acid (UA) and dopamine (DA) at neutral pH (7.4) was studied by chronoamperometry and cyclic voltammetry measurements. At working potential of + 0.3 V (vs. Ag/AgCl), N-doped graphene electrode revealed ultra-high sensitivity of 2.06 mA mM(-1) cm(-2) and low limit of detection (LOD) of 0.13 mu M within a concentration range of 0 to 0.6 mM for UA detection. Also, at very higher potential of + 1.8 V (vs. Ag/AgCl), N-doped graphene sensor exhibited a highly selective response toward DA with very low LOD of 4.5 nM and high sensitivity of 7.63 mA mM(-1) cm(-2) in a broad linear concentration range from 0.1 to 100 mu M. Furthermore, the performance of UA and DA sensors in the real blood sample was satisfactory.