An amperometric nitrite sensing platform with enhanced sensitivity based on copper nanoparticle/nanostructured polyaniline hydrogel nanocomposite

In this study, we have introduced a three-dimensional polyaniline hydrogel (3D-PANIH) with incorporated Cu nanoparticles (CuNPs), which allows for facile fabrication of an electrochemical sensor for sensitive determination of nitrite. The value of this nanocomposite has been highlighted through the comparison of sensing property of the fabricated sensor with most other nitrite sensors reported recently. The sensing property of the sensor based on CuNPs/3D-PANIH nanocomposite was investigated by cyclic voltammetry and amperometric current–time. The electrochemical kinetics reveals that nitrite electrooxidation involves two electrons and two protons in an electrode reaction. The electrochemical sensor presented substantially enhanced electrocatalytic oxidation of nitrite in acidic medium, with an excellent sensitivity of 139.3 μA mM −1  cm −2 , a low detection limit of 0.07 μM, and a broad linear range (0.2–4300 μM). From a broader perspective, the present work may exploit the opportunities for a novel electrochemical sensing platform based on 3D-PANIH. Graphical abstract