Highly sensitive and label-free electrochemical detection of cardiac myoglobin using an Au/Co-BDC@MD-based Immunosensor

Myoglobin (Myo) is the earliest biomarker for the diagnosis of acute myocardial infarction (AMI). Sensitive and reliable Myo assays are essential for timely diagnosis of AMI. In this work, a label-free electrochemical immunosensor was prepared by modifying a glassy carbon electrode (GCE) with a nanocomposite material combining a two-dimensional metal-organic framework (Co-BDC,1,4-benzenedicarboxylate is abbreviated as BDC) hybridized with molybdenum disulfide (MD) nanosheets and loaded with gold nanoparticles (Au NPs). The Au/Co-BDC@MD-modified electrode exhibits good electrochemical properties and biocompatibility, contributing to excellent sensor performance. Under optimal conditions, the linear range of the proposed electrochemical sensor was from 10 fg/mL to 10 ng/mL with a limit of detection (LOD) of 10.03 fg/mL (S/N = 3). In addition, the sensor possessed good specificity, reproducibility and stability. Meanwhile, the amount of Myo in serum was detected with recoveries of 96.9–98.5 % (RSD, 0.31–1.02 %). Therefore, the constructed immunosensor is important for the sensitive and accurate detection of Myo and the early diagnosis of AMI.