Single-Walled Carbon Nanotube-Integrated Immunochromatographic Assay for Rapid and Specific Detection of Helicobacter pylori in Food

Helicobacter pylori ( H. pylori ), a major foodborne pathogen, necessitates rapid and sensitive detection methods to mitigate infection risks. Current gold-standard techniques like real-time PCR are limited by cost, equipment dependency, and impracticality for on-site food safety monitoring. This study introduces a novel single-walled carbon nanotube (SWCNT)-integrated colloidal gold immunochromatographic assay (SWCNT/CGIC) for rapid H. pylori detection in food matrices. SWCNT-conjugated monoclonal antibodies targeting H. pylori GP1 antigen were optimized for colloidal gold labeling. The assay’s sensitivity, specificity, and stability were evaluated using artificially contaminated food samples (milk, vegetables and meat), with real-time PCR as the reference method. Cross-reactivity was tested against common foodborne pathogens, and interference resistance was assessed under varying pH, microbial loads, and saliva concentrations.The SWCNT/CGIC assay showed a detection limit of 1×10³ copies/mL and high specificity, with no cross-reactivity against other microbes. Results were obtained within 15 minutes, outperforming conventional methods like real-time PCR (4–6 hours) and bacterial culture (3–5 days). The assay was validated with standard ( H. pylori ATCC 43504) and clinically isolated ( H. pylori SYHP 170611) strains, as well as artificially contaminated food samples including milk, vegetables, and meat. The SWCNT/CGIC assay provides a rapid (< 15 minutes), cost-effective, and user-friendly alternative for on-site H. pylori detection in food, particularly in resource-limited settings. While less sensitive than PCR at ultra-low bacterial loads, its operational simplicity and portability make it ideal for food safety inspections. This innovation highlights the potential of nanomaterial-enhanced diagnostics in combating foodborne H. pylori transmission.