A novel method for multiple cardiovascular disease biomarker detection using a SERF-based microfluidic platform

As cardiovascular diseases (CVDs) are the leading cause of death worldwide, it is of great importance to realize a rapid and sensitive diagnosis. Multiple CVD biomarker detection, which holds higher accuracy and speed of early CVD diagnosis, is becoming a promising alternative to single biomarker analysis. Cardiac troponin I (cTnI), C-reactive protein (CRP), brain-type natriuretic peptide (BNP), and heart fatty acid binding protein (H-FABP) are four significant diagnostic biomarkers for CVDs. Among the several methods for biomarker detection, such as optical, magnetic, mechanical, and electrical methods, the magnetic method stands out because of its stability, low toxicity, noninvasive detection, facile manipulation with an external magnetic field, and immunity to the interference of background light. At present, the lack of multiplexing capability, the imprecision of magnetic signal localization, and the agglomeration and non-specific adsorption of magnetic nanoparticles all limit the clinical application of magnetic detection. This paper presented a novel method for multiple CVD biomarker detection using a spin exchange relaxation-free (SERF)-based microfluidic platform. One or more SERF atomic magnetometers were used to scan the remanent field of magnetic labels to detect four CVD biomarkers in 70 min, with a detection limit of 1.88 pg/mL (cTnI), 1.58 pg/mL (CRP), 1.45 pg/mL (BNP), and 1.71 pg/mL (H-FABP). The results showed two-dimensional magnetic fields with a resolution of submillimeter level and a sensitivity of pT level. The measurement technique provides a new magnetic methodology for applications in clinical diagnosis. •A SERF-based microfluidic platform realizes multiple CVD biomarker detection.•A method of 2D magnetic field mapping by atomic magnetometers is proposed.•An integrated microfluidic chip has the merits of automatic operation, fast reaction, less reagent, and small size.•A high sensitivity with a detection limit of a few pg/mL for multiple CVD biomarkers is achieved.