Dual-modal lateral flow immunoassay based on cauliflower-like ReS2@Pt core-shell nanospheres mediated ultra-sensitive detection of deoxynivalenol in food samples

Abstract

Deoxynivalenol (DON) is a highly toxic secondary metabolite that poses a substantial threat to global human and animal health. However, existing detection technologies are often constrained by limited sensitivity, poor selectivity, or the high costs associated with instrumentation. Consequently, the development of rapid, low-cost, and highly sensitive biosensors for the detection of DON is of paramount importance for ensuring food safety. In this study, we synthesized the precursor of ReS₂ nanospheres using a relatively simple one-step hydrothermal method. Subsequently, Platinum (Pt) was grown in situ on the surface of the ReS₂ nanospheres via hydrothermal reduction, resulting in the formation of cauliflower-like ReS₂@Pt nanospheres. These spheres offer notable advantages, including strong colorimetric signal brightness and high anti-body loading efficiency. Surface modification with platinum significantly enhances peroxidase-like activity, broadening the detection range and improving sensitivity. Leveraging this innovation, we developed Colorimetric-LFIA (CR-LFIA) and Catalytic-LFIA (CL-LFIA) assays. Under optimized conditions, the limit of detection (LOD) for DON was determined to be 0.018 ng/mL for CR-LFIA and 6.5 pg/mL for CL-LFIA, representing 5 times and 16 times improvement over AuNPs-based LFIA (0.111 ng/mL), respectively. Moreover, the detection linear range of CL-LFIA is expanded by 2.5 times compared to CR-LFIA. Validation with real samples demonstrated recovery rates between 90.33% and 110.64%, affirming method stability and repeatability. The developed dual-modal LFIA detection system (D-LFIA) employing ReS2@Pt NPs holds promise for ultra-sensitive detection, with potential applications in expanding the detection range of various substances.