Voltammetric sensor based on glassy carbon electrode modified with hierarchical porous carbon, silver sulfide nanoparticles and fullerene for electrochemical monitoring of nitrite in food samples

This paper reports the development of a voltammetric sensor using glassy carbon electrode based on hierarchical porous carbon (HPC) with silver sulfide nanoparticles (Ag2SNP), Nafion and fullerene (C60) for the determination of nitrite in foods. Raman spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray were used to characterize the morphology and composition of the materials. The use of HPC and C60 in the construction of the electrode contributed toward the enlargement of the specific surface area and the improvement of the electrochemical performance of the device. The electrochemical behavior of nitrite in different electrodes was evaluated by cyclic voltammetry in the potential range of 0.4 - 1 V. Using the optimal conditions, a linear response ranges of 4.0- 148 μmol L-1, a limit of detection of 0.09 μmol L-1 and a sensitivity of 0.05 μAμmol L-1 cm-2 were obtained. The results showed that the proposed method can selectively detect nitrite in the presence of other compounds without interference and with good stability. The proposed method was successfully applied for the detection of nitrite in food samples where it demonstrated a good degree of accuracy and satisfactory efficiency.