A MnOOH-Polyaniline Nanocomposite Modified Gold Electrode for Electrochemical Sensing of Nitrite

A novel non-enzymatic nitrite sensor was fabricated by immobilizing MnOOH-PANI nanocomposites on a gold electrode （Au electrode）. The morphology and composition of the nanocomposites were investigated by transmission electron microscopy （TEM） and Fourier transform infrared spectrum （FTIR）. The electrochemical results showed that the sensor possessed excellent electrocatalytic ability for NO2 oxidation. The sensor displayed a linear range from 3.0 μmol·L^-1 to 76.0 mmol·L^-1 with a detection limit of 0.9 μmol·L^-1 （S/N=3）, a sensitivity of 132.2 μA·L·mol^-1·cm^-2 and a response time of 3 s. Furthermore, the sensor showed good reproducibility and long-term stability. It is expected that the MnOOH-PANI nanocomposites could be applied for more active sensors and used in practice for nitrite sensing.