▎ 摘　　要

A novel hemoglobin (Hb) electrode modified with Au nanorods (AuNRs) and graphene oxide sheets (GOs) coated by polydopamine (Pdop) (GOs@Pdop) was fabricated and used for highly selective and sensitive determination of nitrite (NO2-) and hydrogen peroxide (H2O2). The electrochemical characteristics of the sensor were studied by cyclic voltammetry and chronoamperometry. The GOs@Pdop composite was characterized by Fourier transform infrared (FTIR), ultraviolet-vis absorption spectroscopy (UV-vis) and transmission electron microscopy (TEM). The system was optimized to realize a reliable determination of NO2- at 0.7 V with a detection limit of 2.5 x 10(-8) M and H2O2 at -0.2 V with a detection limit of 2.0 x 10(-6) M (S/N = 3). The apparent Michaelis-Menten constants (K-M(app)) were calculated to be 0.13 mM for NO2- and 0.70 mM for H2O2. Moreover, the sensor obtained from this study exhibited high sensitivity, good reproducibility, and long-term stability.