A nitrite and hydrogen peroxide sensor based on Hb adsorbed on Au nanorods and graphene oxide coated by polydopamine

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 (NO2a?’) 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 NO2a?’ at 0.7 V with a detection limit of 2.5 ?— 10a?’8 M and H2O2 at a€“0.2 V with a detection limit of 2.0 ?— 10a?’6 M (S/N = 3). The apparent Michaelisa€“Menten constants (KappM) were calculated to be 0.13 mM for NO2a?’ and 0.70 mM for H2O2. Moreover, the sensor obtained from this study exhibited high sensitivity, good reproducibility, and long-term stability.