The Use of Iron-Cobalt Sulphide Electrodes Decorated with Silver Nanoparticles as a Sensitive and Selective Sensor for Nitrite Determination in Different Meat Products

In this study, silver nanoparticle-decorated iron cobalt sulphide (Ag@FeCoS₂) nanostructures were synthesized on the surface of a pencil graphite electrode (PGE). The resulting modified electrode obtained was used to determine the nitrite content in four different meat products (pastırma, bologna-type sausage, heat-treated sucuk, and ham) sourced from the same brand and widely consumed in the Turkish market. The fabricated Ag@FeCoS₂ electrode demonstrated high performance in amperometric nitrite detection, with a linear detection range (0.1 to 2.5 mM), high sensitivity (1759 μA mmol/L), and a low detection limit (0.29 μmol/L). The nitrite results obtained by the electrochemical method showed recoveries ranging from 99.3% to 102.5% compared with the spectrophotometric method. In addition, the physicochemical properties of the meat products, including pH, moisture, protein, fat, and ash contents, were characterized as complementary information on the real food matrices analyzed. Statistically significant differences were observed among the investigated products for these parameters. Overall, the developed Ag@FeCoS₂/PGE sensor provides a practical, accurate, and reliable analytical approach for nitrite determination in processed meat products.