Chiang Mai Journal of Science

This study aimed to investigate the quenching effect of magnetic graphene oxide (Fe₃O₄/GO) on fluorescence. The structure of Fe₃O₄/GO prepared by chemical co-precipitation was characterized, and a new Fe₃O₄/ GO-fluorescence labeling method was established for the rapid detection of Salmonella in chicken. Fe₃O₄/GO and GO were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Results confirmed the chemical structure formation of the nanocomposite. The detection method was used to detect Salmonella target DNA and the Salmonella in artificial simulated contaminated chicken. The assay had a linear response between the target DNA concentration of Salmonella and fluorescence intensity in the 0.005–1 pmol/L concentration range, and the minimum limit of detection was 5 fmol/L (S/N=3). Under optimal conditions, the minimum detection limit for Salmonella-contaminated chicken samples was 10² CFU/mL (S/N=3). The detection method can realize the rapid, selective, and sensitive detection of Salmonella, only requiring 5 h for the entire process. This study may serve as a basis for the detection of Salmonella and other pathogenic bacteria.