Polysilicon Field Effect Transistor Biosensor for the Detection of Cardiac Troponin-I (cTnI)

A highly sensitive and robust polysilicon Field Effect transistor (SiFET) has been developed for the detection of an gold standard biomarker of myocardial infarction (AMI) Cardiac Troponin I (cTnI). This paper reports a polysilicon FET device integrated with a thin film of gold layer as a gate terminal which is biofunctionalized with specific cTnI binding single stranded DNA receptor aptamer to detect cTnI. The reported SiFET is fabricated using standard microfabrication unit processes. The detailed characterization of reported device is performed and thoroughly discussed at different stages of device development. The assessment of bio-interface is also studied using various surface characterization techniques such as Raman spectroscopy, Atomic force microscopy (AFM) and Contact angle measurements. The experimental results showed the significant response for cTnI concentration as low as 0.1 ng ml −1 for label free detection.