Construction and feasibility research in acute myocardial infarction detection based on near-infrared fluorescent SWCNT biosensor

A solid-phase ssDNA-SWCNT NIR fluorescence sensing platform was developed. • Various immobilization strategies were explored systematically. • Rapid detection of AMI-related miRNA biomarkers was achieved within 15 min. • The platform shows good sensitivity and specificity, meeting POCT requirements. Acute myocardial infarction (AMI) is a life-threatening cardiovascular emergency caused by acute and persistent obstruction of the coronary arteries, resulting in irreversible necrosis of myocardial tissue. Therefore, point-of-care testing (POCT) is of great importance. Traditional analytical methods, such as cardiac troponin detection, are usually time-consuming. In this study, a solid-phase near-infrared fluorescence biosensing platform based on single-stranded DNA–functionalized single-walled carbon nanotubes (ssDNA–SWCNTs) for the rapid detection of AMI-associated miRNA-208a biomarker was established. The miDNA208a functionalized SWCNTs were constructed by probe ultrasonic fragmentation and ultrafiltration centrifugal purification methods. Then a poly- l -lysine (PLL) immobilization strategy was applied to obtain a uniform and stable fixed sensor. The fluorescence response kinetics, selective recognition capability, quantitative concentration relationship, and long-term storage stability of the sensor were tested to demonstrate its high specificity for the target miRNA-208a compared to nonspecific and mutant sequences in both buffer and serum systems. The results showed that miDNA208a–SWCNT sensors could be used for the early POCT of AMI, providing diagnostic information rapidly, sensitively, and specifically detecting miRNA-208a in serum within 15 min, and has the potential to be expanded to the detection of other disease biomarkers. This platform is easy to operate and enables rapid detection which offers a novel technological solution with clinical translation potential for the early POCT of AMI. Download: Download high-res image (183KB) Download: Download full-size image