cardiovascular diseases (CVDs) are the leading cause of death worldwide, killing over 17 million people yearly. A key biomarker for identifying myocardial infarction (MI) is the regulatory protein Cardiovascular Troponin I (cTnI), released into the blood following heart muscle injury. Significant efforts have been made in recent years to develop highly sensitive biosensors for the detection of cTnI. Field effect transistors (FETs) in general and organic FETs (OFETs) in specific have shown computability in detecting such cordial protein. In this study, we provide a complete attempt to fabricate and characterize polyaniline nanofiber (PANI-NFs) OFET for biosensing applications. The FTIR spectrum of PANI-NFs is examined before and after pAbs immobilization. To study the biosensor performance parameters, the biomarker drain current is investigated against the cTnI biomarker concentrations. The proposed OFET recorded high sensitivity of 484 nA.(g/mL) -1 , with a minimum detection limit (0.36 pg/mL) and power consumption varying from 7 μW to 11.4 μW. Finally, the biosensing repeatability was examined regarding variation in the P-FET device and the biasing conditions.