An electrochemical biosensor based on a myoglobin-specific binding peptide for early diagnosis of acute myocardial infarction

In this study, a simple, highly sensitive electrochemical biosensor for myoglobin was developed using a myoglobin-specific binding peptide as a sensing probe. A peptide (Myo-3R7, CPSTLGASC, 838 Da) identified by phage display and that specifically binds to myoglobin was covalently immobilized on a gold electrode functionalized via a dithiobis(succinimidyl propionate) (DSP) self-assembled monolayer (SAM). The peptide immobilization was confirmed with fluorescence microarray scanning and cyclic voltammetry (CV). The electrochemical performance of the biosensor with respect to myoglobin was characterized by CV and differential pulse voltammetry (DPV) using Fe(CN) ₆ ^3- /Fe(CN) ₆ ^4- as a redox probe. We successfully detected myoglobin in a broad working range of 17.8 to 1780 ng mL ^-1 with a correlation coefficient (R ² ) of 0.998. The estimated limit of detection (LOD) was fairly low, 9.8 ng mL ^-1 in 30 min. The electrochemical biosensor based on a myoglobin-specific binding peptide offers sensitivity, selectivity, and rapidity, making it an attractive tool for the early detection of cardiac infarction.