Usefulness of enzyme-free and enzyme-resistant detection of complement component 5 to evaluate acute myocardial infarction

Biomedical kits of simple design, low cost and high reliability are essential for the future development of point-of-care medicine, and reducing the complexity of a biosensing design can greatly lower its cost while improving its robustness. This work reports our effort towards this direction: the traditional antibody-based target recognition and enzyme-based signal amplification are replaced with synthetic probe and metal ion-catalyzed cross-linking reaction. Specifically, we have designed a sensing method to detect complement component 5 (C5) protein, using aptamer as a molecular probe, and calcium ion catalyzed amination of carboxyl as the methods of targeting and signal generation, respectively. This design has been successfully brought to detect the C5 in blood samples from healthy volunteers, patients with unstable angina and those with acute myocardial infarction. The signal response is higher in patients with acute myocardial infarction than the other two groups, and a correlation has been detected between the signal response and cardiac remodeling and dysfunction. These results may point to the potential of this method as a fast and low-cost kit for C5 detection useful for the myocardial infarction-related scenario.