Ultrasensitive magnetic nanomechanical biosensors for simultaneous detection of multiple cardiovascular disease biomarkers in a single blood drop

Cardiovascular disease (CVD) is the number one cause of death, and the early prevention of CVD is considered the most useful and cost-effective intervention strategy, highlighting the critical need for frequent and long-term monitoring cardiac abnormalities. However, traditional blood test methods often require considerable volumes of blood (>10 mL), which could burden physical health, especially for individuals in poor health. Here, we report a novel magnetic nanomechanical sensor (MNS) capable of simultaneously detecting multiple CVD biomarkers (brain natriuretic peptide (BNP), cardiac troponin I (cTnI) and creatine kinase MB (CK-MB)) in a single drop of blood (<1 μL). Relying on the force-sensitive microcantilevers and robust magnetic force, MNS can directly detect blood samples with a detection sensitivity for BNP as low as 0.1 pg/mL. Moreover, we improved the MNS sensitivity by reducing nonspecific adsorption and focusing the force on specific locations on the sensor surface. The effectiveness of the MNS was demonstrated through the detection of samples from clinical CVD patients and healthy individuals. Given its ultrasensitive, trace-sample requirement, and ability to monitor multiple biomarkers, the MNS holds significant potential for frequent and long-term monitoring—not only for CVD but also for the prevention and management of other chronic diseases.