الفهرس 
hapter I I.Introduction, Literature Review and ObjectiveOnly 14 pages are availabe for public view
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Abstract
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. Biosensors are important devices that convert the biological impulse in an electrical signal and have been used for a wide variety of applications ranging from environmental to agriculture and biomedicine. Field effect transistors (FETs) in general and organic FETs (OFETs) in specific have shown computability in detecting such cordial protein.
In this thesis, we provide a complete attempt to fabricate and characterize polyaniline nanofiber (PANI-NFs) OFET for biosensing applications. Organic field-effect transistors (OFETs) have shown potential market in many low-power sensing applications. Toward that, the fabrication of sharp on/off OFET is essential. Herein, we present an attempt to fabricate OFET using polyaniline (PANI), in the form of PANI-nanofibers with a fiber diameter of 75 nm, as an active semiconductor layer. The polymethyl methacrylate (PMMA) is utilized as a gate dielectric with an aluminum bottom electrode. Top electrodes for both source and drain were fabricated of gold. The Primary, in-situ polymerization method is used in preparing the PANI as a semiconductor film. The morphological and optical properties of PMMA thin-film as well as PANI nanofibers were investigated using SEM, FTIR, AFM, and UV-Vis. Spectrometer. in addition, The FTIR
spectrum of PANI-NFs is examined before and after pAbs immobilization. The bandgap energy of PANI nanofibers was observed to be 2.2 eV. Consequently, the I-V characteristics of OFET were studied for the device, showing a sharp sub-threshold response. An ultra-low threshold voltage of 0.17 V was recorded. The biomarker drain current is investigated against the cTnI biomarker concentrations to study the biosensor performance parameters. The proposed OFET recorded high sensitivity of 484 nA.(g/mL)-1, with a minimum detection limit (97 fg/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.
Overall, this research contributes to the development of a highly sensitive and low-power biosensor for cTnI detection. The fabricated PANI-NFs OFET biosensor offers potential for accurate and reliable detection of cardiac biomarkers, enabling advancements in the diagnosis and treatment of cardiovascular diseases.