High sensitive and multiple detection of acute myocardial infarction biomarkers based on a dual-readout immunochromatography test strip

Immunochromatography test strip (ICTS) displayed high advantages in screening acute myocardial infarction (AMI) biomarkers. However, the low sensitivity and nonquantitative results seriously limited its clinical application. Herein, we designed a highly sensitive, quantitative and dual-readout ICTS for assaying multiple AMI biomarkers based on magnetic nanoparticles (MNPs) quenching the fluorescence of Cy5, which was labeled on capture antibodies on test (T) lines. The changes of fluorescent intensity caused by MNPs nanoprobes enabled us to sensitively quantify cTnI and CK-MB for early diagnosis of AMI in 15 min with a corresponding detection limit of 0.049 ng/mL and 0.085 ng/mL, respectively. Meanwhile, the aggregations of MNPs on T lines allowed colorimetric readout in 2 min for rapid diagnosis of emergent and severe AMI patients. Furthermore, the detection results of 30 clinical serum samples were coincident with those by electrochemiluminescence immunoassay. So this approach is promising a new avenue for clinical diagnosis and prognosis of AMI.