Fully Integrated Microfluidic Platform Coupled with Magnetic Sensing for Rapid Detection of Cardiovascular Disease Biomarkers

Cardiovascular diseases (CVDs), especially acute myocardial infarction (AMI), represent a major global health challenge with high morbidity and mortality rates. Early and precise diagnosis of AMI is vital for initiating prompt treatment, minimizing myocardial damage, and improving patient survival. Heart-type fatty acid binding protein (H-FABP) has emerged as a specific biomarker for the early detection of AMI, particularly within the initial hours following myocardial injury. However, the application of traditional biomarker detection is often constrained by complex system configurations and time-consuming sample preprocessing procedures, which hinder their efficiency in large-scale screenings. Therefore, the development of simple and automated diagnostic methods for the quick and accurate identification of biomarkers is particularly significant. The magnetic method, which shows high stability, facile manipulation with an external magnetic field, and low background noise, stands out in comparison to conventional detection methods such as optical, mechanical, and electrical methods. Microfluidic chips not only further enhance detection sensitivity but also enable the complete on-chip pretreatment of biomarkers, allowing for their rapid and efficient detection. In this study, a fully integrated microfluidic platform coupled with magnetic sensing was proposed for the detection of biomarkers. The device integrates a multifunctional microfluidic chip equipped with an active-passive mixing module, a microcoil, and a magnetic sensing region. By employing a spin-exchange relaxation-free (SERF) atomic magnetometer, a high-resolution magnetic field mapping, with submillimeter spatial precision and detection sensitivity in the pT range, was constructed. The detection limit of H-FABP reached 1.57 pg/mL, with the entire detection process completed in 25 min. Owing to its compact design, high sensitivity, and quick processing capability, the developed system holds strong potential for rapid point-of-care diagnostics and early disease screening in clinical applications.