CNT based high-k dielectric ion sensitive field effect transistor based cholesterol biosensor

Carbon nanotube (CNT) based high-K dielectric ion sensitive field effect transistor (ISFET) based cholesterol biosensor has been realized using Polyethylenimine (PEI) doped CNT channel and nanocomposite of potassium doped CNT with polypyrrole as sensing membrane.Device has been fabricated using solution method and electrical characterization of the device has been carried out after immobilization of enzyme cholesterol oxidase (ChO_x) in presence of PBS solution.Device has shown a wide dynamic range (0.5 to 25mM), a good sensitivity of 60 mV/decade,low response time (~1 s), low detection limit (0.23 mM), good stability (7 months) and high selectivity (interference ~1.8%).