The fast, and highly sensitive estimation of cardiac troponin T (cTnT) is crucial for the early identification of acute myocardial infarction (AMI). The electrochemical immunoassay-based (EIB) sensors are highly promising for this purpose, as they offer precise measurements and can be directly assessed in intricate matrices, including blood. To increase sensitivity, EIB sensors use nanomaterials or amplification processes, which can be laborious to develop. With this, we develop an electrochemical immunosensor for the sensitive detection of cardiac troponin T (cTnT). The sensing platform is composed of functionalized triangular carbon quantum dots stabilized gold nanoparticles which are integrated with boron nitride nanosheets (caf-TCQDs@AuNPs on HO-BNNS). Ferrocene carboxylic acid (Fc-COOH) serves as the signal label. The composite was developed and examined using several techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), cyclic voltammetry, and chronocoulometry. The caf-TCQDs@AuNPs supported on HO-BNNS, have a large surface area and excellent electrical conductivity, and serve as an effective platform for the immobilization of anti-cTnT monoclonal antibodies via carbodiimide coupling. The Fc-COOH, functioning as a signal label through the oxidation process, was integrated with caf-TCQDs@AuNPs on the HO-BNNS platform to establish an electrochemical immunosensor for the detection of cTnT. The electrochemical immunosensor demonstrated excellent performance for the determination of cTnT under optimal conditions, exhibiting a linearity range spanning from 0.0001 to 100 ng mL-1, accompanied by a low detection limit of 0.0013 ng mL-1. Notably, the immunosensor revealed high specificity, as well as excellent levels of reproducibility and reliability for the examination of human serum samples.