Cardiac Troponin I Biosensors: Innovations in Real-Time Diagnosis of Cardiovascular Diseases

Abstract

Cardiac troponin I (cTnI) is a crucial biological macromolecule found in the contractile apparatus of cardiac myocytes, exclusively expressed in cardiomyocytes. It is released into the bloodstream upon cardiac tissue injury, serving as a vital biomarker for the early detection of various heart diseases. Despite advancements in cTnI diagnostics and cardiovascular disease (CVD) detection, there is an ongoing need for more effective early diagnostic methods and innovative approaches. Current CVD diagnosis often relies on clinical signs and symptoms, supplemented by molecular imaging (MI) or biomarkers associated with CVD. However, challenges remain regarding the reliability, specificity and accuracy of analyses for myocardial infarction, particularly in its early stages. Emerging nanomaterial systems present promising solutions for enhancing diagnostic tools due to their unique physical and chemical properties. Various nanomaterials, such as gold nanoparticles, carbon nanotubes, quantum dots, lipids and polymer nanoparticles, are paving new pathways for cardiac disease detection. The advancements in nanomaterial science offer exciting opportunities for cardiac screening. This article provides a comprehensive overview of these advancements, categorizing research efforts focused on both optical and electrochemical platforms, thereby contributing to the evolution of cardiac screening methodologies and addressing the critical need for reliable early diagnostic solutions.

Keywords: biomedical engineering; biosensors; cardiac troponin I (cTnI); cardiovascular diseases (CVDs); nanodiagnoses.

FIGURE 1

This diagram illustrates the components involved in muscle contraction, including the troponin complex (troponin I, troponin C, troponin T), tropomyosin, actin filaments, myosin heavy and light chains, and the Z‐disk. The Z‐disk anchors the actin filaments, whereas tropomyosin covers the myosin‐binding sites on actin. When calcium binds to troponin C, it triggers a conformational change that exposes these binding sites, allowing myosin heads to attach to actin. This interaction initiates the power stroke, resulting in muscle contraction as actin filaments are pulled toward the centre of the sarcomere.

FIGURE 2

This diagram illustrates the structure of various biosensors, including immunosensors, which detect specific antigens using antibodies, and genosensors, which identify specific nucleic acid sequences. It also highlights analytical methods such as cyclic voltammetry (CV) for studying electrochemical properties, differential pulse voltammetry (DPV) and square wave voltammetry (SWV) for sensitive detection of analytes, amperometry for measuring current from oxidation or reduction reactions, coroamperometry for real‐time concentration analysis and surface plasmon resonance (SPR) for real‐time measurement of biomolecular interactions. Together, these biosensor types and methods enable precise detection and quantification of biological and chemical substances, advancing diagnostics and research.

FIGURE 3

This diagram depicts a molecularly imprinted polymer (MIP)‐based biosensor designed for the selective detection of cTnI, a key biomarker for diagnosing myocardial infarction. The biosensor is created through a molecular imprinting process, where cTnI serves as a template to form specific binding sites within a polymer matrix. After removing the template, the MIP selectively binds cTnI, generating measurable signals through electrochemical or optical transduction methods. Advantages of MIP‐based biosensors include rapid diagnosis, stability, reusability and cost‐effectiveness. Future developments may involve integrating these biosensors with microfluidic systems, enhancing sensitivity and enabling the simultaneous detection of multiple cardiac biomarkers, representing a significant advancement in cardiac health diagnostics. cTnI, cardiac troponin I. Source: Adapted from Yola and Atar [49].

FIGURE 4

This diagram depicts an SPR‐based biosensor designed for the detection of cTnI, an important biomarker for diagnosing myocardial infarction. The biosensor features a thin gold film coated with specific antibodies that selectively bind to cTnI. When light is directed at the metal surface, surface plasmons are excited, resulting in a change in the refractive index upon cTnI binding, which is detected as a shift in the SPR signal. This method provides high sensitivity and real‐time monitoring, making it suitable for clinical diagnostics. Advantages include label‐free detection and rapid response times. Future developments may enhance sensitivity, enable multiplexing for simultaneous detection of multiple biomarkers and integrate with portable devices for POC applications, improving cardiac health monitoring. cTnI, cardiac troponin I; SPR, surface plasmon resonance. Source: Adapted from Çimen et al. [52].