Dielectric-Modulated Junctionless Carbon Nanotube Field-Effect Transistor as a Label-Free DNA Nanosensor: Achieving Ultrahigh Sensitivity in the Band-to-Band Tunneling Regime

This article introduces a novel label-free deoxyribonucleic acid (DNA) nanosensor based on a coaxially gated junctionless carbon nanotube field-effect transistor (JL CNTFET). The proposed DNA sensor is computationally investigated using numerical methods within the nonequilibrium Green’s function (NEGF) quantum simulation framework. The nanosensor uses the principle of dielectric modulation, utilizing two laterally open cavities for DNA sensing. The combination of the junctionless (JL) design, laterally open cavities, and the straightforward biosensing principle makes the JL CNTFET-based DNA sensor easily manufacturable and operable. The proposed DNA nanosensor operates in the band-to-band tunneling (BTBT) regime, targeting ultrahigh sensitivity. The computational results reveal that the JL CNTFET-based label-free DNA nanosensor exhibits a substantial DNA-induced modulation in tunneling current by affecting the BTBT windows. As a result, it achieves remarkable sensitivity in the BTBT regime. This DNA nanosensor offers valuable advantages such as ease of nanofabrication, reliable manufacturing, energy efficiency, compact size, and label-free DNA detection, making it a compelling candidate for advanced complementary metal–oxide–semiconductor (CMOS)-based label-free DNA sensing applications.