Phage tail fiber protein-based fluorescence immunochromatographic test strip for rapid and sensitive detection of shiga toxin-producing Escherichia coli O103.

Shiga toxin-producing Escherichia coli (STEC) poses a severe threat to global public health and food safety, creating an urgent need for rapid and sensitive detection of STEC. Herein, a novel fluorescent immunochromatography test strip (FITS) is reported for the detection of STEC O103 using QDs-loaded dendritic silica spheres (named SQS) as a signal tag. The novel FITS employs a phage tail fiber protein as a superior antibody alternative, which was functionalized on the SQS and demonstrates excellent capability for bacterial recognition and binding. This assay successfully achieves the sensitive detection of STEC O103 (2.2 × 102 CFU/mL) within 12 min, achieving performance comparable to conventional PCR while significantly reducing assay time. More significantly, the results of the FITS in real samples were in good agreement with those from PCR, exhibiting comparable accuracy and reproducibility. Given its rapidity, simplicity, sensitivity, and visual detectability, the proposed FITS stands out as an ideal approach for STEC O103 detection and shows great promise for the early warning and diagnosis of bacterial infections.