A manual and portable centrifuge combined with a paper-based immunoassay for myocardial infarction diagnosis

Myocardial infarction (MI) causes hundreds of thousands of deaths annually. Early diagnosis of MI by detecting the concentration of troponin I in plasma can help limit mortality rates. However, plasma separation and early diagnosis are particularly difficult to achieve in resource-limited settings. In this study, we demonstrate a manual and portable centrifuge along with a paper analytical device to measure troponin I for early MI diagnosis. With this so-called “Handfuge,” pure plasma can be achieved with a yield of up to 47.1% and purity as high as 99.9% in less than 3 min without electricity. The resulting plasma can then be directly used for detecting troponin I using a paper-based enzyme-linked immunosorbent assay (ELISA), with a detection limit as low as 0.03 ng/mL. The whole detection process consumes just 10 µL of blood, which is similar to the volume obtained by a clinical finger-prick. The proposed centrifuge together with the paper analytical device possesses the potential to replace existing techniques in troponin I detection for early MI diagnoses in resource-limited regions of the world.