This study will use a self-powered stream (STP) technique to develop a point-of-care cassette and based on the urgent need of the Acute myocardial infarction (AMI), we choose Troponin I as the detection target. The integration of the whole blood separation microfluidic cassette and magnetic control platform are used to complete the ultra-low concentration of biomarker. To achieve a high detection goal of the high sensitivity and accuracy of Troponin I, the study has developed three innovative modules: 1. To separate plasma from whole blood sample using the self-powered stream device 2. To locate the reagent at reagent well when plasma separation, a unique design that apply liquid-air surface tension to form the air-gate between reagents. 3. A Troponin I diagnostic cartridge with high sensitivity of 100 pg/mL, coefficient of variation (CV) ≤10%, and assay time ≤ 20 min.