Sensitive detection of hepatitis C virus using a catalytic hairpin assembly coupled with a lateral flow immunoassay test strip.

Currently, PCR is the gold standard for the detection of hepatitis C virus (HCV). However, the PCR technique is complicated and time-consuming, which prevents its application and, clinical point-of-care testing (POCT). Herein, we report a POCT method with simplicity, high sensitivity and specificity, which consists of a catalytic hairpin assembly (CHA) signal amplification system coupled with a lateral flow immunochromatographic (LFIA) test strip for the detection of HCV. Two ingeniously designed hairpin probes were hybridized to form the H1-H2 duplex in the presence of the target DNA. The catalytic hairpin assembly which was characterized of isothermal and enzyme-free, was accomplished within 40 min and the reaction was then applied to a LFIA test strip. Only the H1-H2 duplex labeled with both digoxin and biotin could be captured by the test strip, and the fluorescence value was determined. In addition, we evaluated the application potential for the detection of clinical samples. The reported method demonstrated high sensitivity with a detectable minimum concentration at 1 fM and showed a good linear range from 10 nM to 10pM, and high specificity for various mismatched sequences. The results demonstrated that clinically positive samples could be successfully detected. In conclusion, the reported method is simple, rapid, and free of large-scale equipment. POCT is expected to be useful for HCV detection in clinic.