Advanced nanomaterials for cardiac troponin I biosensing in rapid and point-of-care diagnosis

Cardiovascular diseases (CVDs remain the primary cause of global mortality, justifying for nearly 17.9 million deaths annually. Rapid and precised diagnosis of acute myocardial infarction (MI) is therefore nitpicking. In cardiac biomarkers, cardiac troponin I (cTnI) provides greater sensitivity and specificity compared to myoglobin and creatine kinase-MB, upholding it as the clinical gold standard. However, traditional laboratory-based troponin assays require sophisticated fabric and prolonged processing times (1–2 h), limiting their effectiveness in emergency and constraint settings. Recent advances in point-of-care (POC) biosensing technologies, enabled by innovations in nanomaterials and surface engineering, have greatly improved the pace and sensitivity of cTnI detection. Next-generation biosensors demonstrate detection limits as low as 0.001 pg/mL with response times of 5–30 min. This poses a major challenge for cTnI biosensors in enabling rapid and easy detection. Recent developments in cTnI biosensors, such as metal nanoparticles (gold and silver), conductive polymers (polypyrrole and PEDOT: PSS), metal oxide nanostructures (ZnO and TiO₂), and flexible and rigid substrates, are presented in this article. The strategies that reduce biofouling and promote stability in complex biological matrice include biomimetic coatings, polydopamine, protective peptides, and polyethylene glycol (PEG). Additionally, the use of amplification techniques, microfluidic platforms, aptamer-based methods of detection, and artificial intelligence (AI)-assisted data analysis facilitates clinically relevant working capabilities with an increased degree of credibility for advanced cTnI biosensors. Despite ongoing issues with reproducibility, long-term stability, and regulatory translation, advanced cTnI biosensors provide a strong possibility for quick diagnosis, continuous monitoring, and improved worldwide access to cardiovascular medical care.