A novel metal-organic framework based electrochemical immunosensor for the rapid detection of Salmonella typhimurium detection in milk

Abstract

Salmonella is one of the most prevalent pathogens causing foodborne diseases. In this study, a novel electrochemical immunosensor was designed for the rapid and accurate detection of Salmonella typhimurium (S. typhimurium) in milk. Platinum nanoparticles and Co/Zn-metal-organic framework @carboxylic multiwalled carbon nanotubes in the immunosensor acted synergistically to enhance the sensing sensitivity and stability. The materials and sensors were characterised using X-ray diffractometry, scanning electron microscopy, Fourier-transform infrared spectroscopy, differential pulse voltammetry, cyclic voltammetry, and other techniques. The optimised immunosensor showed a linear response for S. typhimurium concentrations in the range from 1.3 × 10² to 1.3 × 10⁸ CFU mL^-1, with a detection limit of 9.4 × 10¹ CFU mL^-1. The assay also demonstrates good specificity, reproducibility, stability, and practical application potential, and the method can be extended to other foodborne pathogens.

Keywords: Electrochemical immunosensor; Food safety; Metal–organic framework; Multiwalled carbon nanotubes; Platinum nanoparticles; Salmonella typhimurium.