A novel electrochemical sensor based on gold nanorods and Nafion-modified GCE for the electrocatalytic oxidation of nitrite

The high-quality CTAB-stabilized gold nanorods (Au NRs) were prepared by the way of seed-mediated protocol. The microstructure and composition of the Au NRs were identified by transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and UV–visible spectroscopy. Further, a novel non-enzymatic electrochemical sensor of nitrite based on Au NRs–Nafion-modified glassy carbon electrode (GCE) was successfully developed. Under the optimum experimental conditions, the electrochemical behaviors of nitrite on the Au NRs–Nafion-modified GCE were systematically studied by electrochemical impedance spectroscopy, cyclic voltammetry and chronoamperometry. The electrochemical investigations indicated that the Au NRs–Nafion-modified GCE had a wide linear range of 3.0 × 10−6–6.0 × 10−3 mol L−1, an acceptable sensitivity of 130.9 ± 0.05 μA mM−1 cm−2, a fast response time of 3 s and a low detection limit of 0.64 ± 0.02 μmol L−1 at the signal-to-noise ratio of 3 (S/N = 3). Additionally, the electrochemical sensor also showed good stability and favorable anti-interference capability for the detection of nitrite.