Cardiac troponin sensing via carbon dot-based optical biosensors: advances and clinical opportunities

Cardiovascular diseases, particularly acute myocardial infarction (AMI), remain a leading cause of mortality worldwide, necessitating rapid and accurate diagnostic strategies. Cardiac troponins, especially cardiac troponin I (cTnI) and T (cTnT), are established as gold-standard biomarkers for myocardial injury; however, conventional detection methods suffer from limitations in sensitivity, time consumption, and requirement of complex instrumentation. In recent years, carbon dots (CDs)-based optical biosensors have emerged as promising alternatives due to their excellent photoluminescence properties, biocompatibility, and tunable surface chemistry. This review systematically discusses the role of CDs in fluorescence, colorimetric, and chemiluminescence-based detection of cardiac troponin, highlighting their sensing mechanisms, analytical performance, and integration into portable microfluidic and point-of-care platforms. Furthermore, recent advancements, including Förster resonance energy transfer (FRET)-based systems, nanozyme-assisted assays, and multiplex chemiluminescence platforms, are critically evaluated. Finally, current challenges, limitations, and future perspectives are addressed to provide insights into the development of next-generation CDs-based diagnostic technologies for early and reliable cardiovascular disease detection.