RESUMEN
Bacterial toxins emerge as the primary triggers of foodborne illnesses, posing a significant threat to human health. To ensure food safety, it is imperative to implement point-of-care testing methods. Lateral flow biosensors (LFBs) based on gold nanoparticles (GNPs) have been commonly used for rapid detection, but their applicationis limited by low sensitivity. Based on the localized surface plasmon resonance and photothermal effect of dual gold nanoparticle conjugates (DGNPs), we developed a smartphone-integrated photothermal LFB (PLFB) with double-enhanced colorimetric and photothermal sensitivity. Through numerical simulations, we verified that DGNPs have significantly enhanced photothermal performance compared to single 15 nm GNPs (SGNPs), and applied DGNPs in PLFB for the detection of staphylococcus enterotoxin A (SEA). The colorimetric and photothermal limits of detection of DGNPs-based PLFB for SEA were 0.091 and 0.0038 ng mL-1, respectively. Compared with the colorimetric detection of the SGNPs-based LFB, the colorimetric detection sensitivity of the DGNPs-based PLFB was increased by 10.7 times, and the photothermal detection sensitivity was further improved by 255.3 times. Moreover, the PLFB exhibits robust reproducibility and exceptional specificity and is applicable for detecting SEA in milk samples. This smartphone-integrated PLFB based on DGNPs allows users to detect toxins simply, conveniently, and quickly and has huge application potential in the field of food safety.
RESUMEN
Rapid and sensitive detection of foodborne pathogenic bacteria is particularly important for the prevention and control of foodborne diseases. The lateral flow strip biosensor (LFSB) is one of the most promising point-of-care detection tools and has been widely used in food safety monitoring. This review introduces recent advances in the detection of foodborne pathogenic bacteria using LFSBs. According to different bacterial biomarkers, we summarize the direct and indirect sensing strategies of bacterial LFSBs. The direct sensing strategies for whole bacterial cells are divided into antibodies, antibody alternatives, and label-free according to the recognition elements. The indirect sensing strategies refer to the detection of bacterial nucleic acids and metabolites. Next, we compare and discuss the applications of direct and indirect sensing strategies. Finally, the existing challenges, future perspectives, and development directions are discussed, which will facilitate the theoretical innovation and practical application for bacterial LFSBs.