Quantum dot-based immunochromatography test strip for rapid detection of Campylobacter jejuni

Campylobacter jejuni is a recognized human foodborne pathogen which is one of the leading causes of human gastrointestinal enteritis worldwide. In stress conditions, C. jejuni is able to enter into a viable but non-culturable state that is difficult to diagnose. Hence a rapid, sensitive, and specific method is required to monitor food and water for natural or intentional contamination by this pathogen. We report a quantum dot (QD)-based immunochromatography test strip (QDITS) for rapid detection of C. jejuni. The QDITS is based on a sandwich type immunoassay with QD fluorescence for sensitive detection. Under optimized conditions, this QD-based fluorescence biosensor exhibits detection of 10(4) CFU/ml in pure culture of C. jejuni which is 10 times more sensitive than colloidal-gold ITS. The improved sensitivity is attributed to the high quantum yield and brightness of the photostable QDs. When the QDITS were tested in 206 chicken samples and 120 beef samples, this exhibited a specificity of 98.5% and 99.1% respectively. On these real samples, the sensitivity of the QDITS was 100% in agreement with traditional culture method. The QDITS that took only 10 minutes to complete hold promise for rapid, sensitive detection of C. jejuni in real samples without the need for sample preparations steps.