Colorimetric analysis of C-reactive protein via 'jellyfish' probe-based exonuclease III-assisted multiple-signal recycles.

C-reactive protein (CRP) is a potential biomarker for evaluating inflammatory responses in patients receiving coronary artery bypass graft surgery. Here, the authors depict a sensitive and reliable colorimetric approach for CRP analysis. In this method, an aptamer specifically binds with CRP and an initiator sequence is released from an arch probe to activate signal amplification. The released initiator sequence hybridizes with the toehold section in the 'jellyfish' probe to form a blunt terminus to induce exonuclease III-assisted signal amplification. The method exhibited a low limit of detection of 1.32 ng/ml and high intraday and interday precision for CRP detection. In summary, this colorimetric approach may provide a potential alternative tool for the evaluation of inflammation in patients receiving coronary artery bypass graft and clinical diagnostics of disease.