LAUSR

The measurement of cardiac troponin‐I (cTnI) is widely used for diagnosing acute myocardial infarction (AMI) diseases because of its myocardial specificity. Packaged microbubble resonators with thin wall are utilized for label‐free and specific detection of cTnI based on whispering gallery mode (WGM). This packaged structure can provide a good protection for the biosensor, improve the anti‐interference ability of the sensor and reduce the system noise. The theoretical detection limit of the biosensors for cTnI in phosphate buffer saline (PBS) is 0.4 ag mL−1 (0.02 aM). Furthermore, we demonstrated that the biosensors can be used to detect cTnI molecules in simulated serum and the theoretical detection limit is also 0.4 ag mL−1 (0.02 aM). These results are much far below the clinical cut‐off value and show a huge application potential for the detection of cardiac biomarkers of AMI.