High Performance CNTENFET with K/PPy/CNT nanocomposite biosensing layer for Cholesterol Detection

Abstract

We have reported a high-performance dual gated carbon nanotube enzyme modified field-effect transistor (CNT-ENFET) for cholesterol detection. To improve the device performance, we have used dual-gate design with high κ dielectric as top gate and low κ dielectric as bottom gate and a nanocomposite of potassium doped carbon nanotube with polypyrrole (K/PPy/CNT) as the biosensing membrane. The device exhibited a good sensitivity (~1.0 V/decade), low response time (~1 s), wide dynamic range (0.1 - 25) mM, wide linear range (2-20 mM), low detection limit (0.11 mM), good stability (7 months) and high selectivity (interference ~1.8 %).