Study on an Electrochemical Immunosensor for Sensitive Detection of Myoglobin Based on Graphene–Nanogold Composite Material

Acute myocardial infarction (AMI) is a highly lethal cardiovascular emergency, and early diagnosis is crucial for improving prognosis. Myoglobin (Mb), as an early biomarker, is of great significance for rapid and sensitive detection. Traditional methods rely on electrocardiography (ECG) and clinical symptom assessment, which can lead to misdiagnosis or delayed treatment due to atypical features. This study developed an electrochemical immunosensor based on graphene-nanogold composite materials (GR-AuNPs) for highly sensitive detection of Mb. The electrochemical performance was analyzed by CV, EIS, and DPV, and the material was characterized by SEM and EDS. The sensor exhibits good linear response within the concentration range of 0.001-100 ng/mL Mb, with a detection limit as low as 0.42 pg/mL (<i>R</i> ² = 0.9885). The sensor does not show significant signal interference in the presence of common blood interference substances such as hemoglobin, albumin, and cytochrome C, demonstrating excellent specificity. Additionally, the sensor has good reproducibility and stability (RSD of 1.57 and 1.34%, respectively). It has also demonstrated good potential for application in actual sample testing. Therefore, this immunosensor has high sensitivity and good stability and is expected to provide a new method for early and rapid diagnosis of AMI.