Determination of nitrite in food specimens using electrochemical sensor based on polyneutral red modified reduced graphene oxide paste electrode

Abstract

This work's purpose was a design a nanocomposite of polyneutral red and reduced graphene oxide paste electrode (pNR/rGO-PE) that may be employed as an accurate and sensitive electrochemical sensor to measurement of nitrite level in real food samples. The electro-polymerization process was employed for the synthesis of pNR/rGO-PE. Results from XRD and SEM analysis proved that NR was successfully electro-polymerized on rGO-PE. The incorporation of rGO nanosheets into conducting NR polymer with synergistic effects improved the electrochemical response of the modified electrode with great selectivity and sensitivity of 0.01511 µA/µM and a stable and broad linear range from 0 to 14000 µM, according to electrochemical studies using CV and amperometry. The low detection limit of the nitrite sensor was 17 nM. The accuracy and validation of the pNR/rGO-PE as a nitrite sensor in prepared meat samples were studied. The attained RSD values (3.56% to 4.78%) and recovery (90.00% to 96.66%) values for amperometry analysis were satisfactory, confirming the applicability and validation of the pNR/rGO-PE results for the determination of nitrite level in food samples.