A detailed investigation of dielectric-modulated dual-gate TMD FET based label-free biosensor via analytical modelling

Abstract

In this work, an analytical model is developed for DM-DG-TMD-FET- based Biosensor including Fringing-field effects. The Analytical model has been developed for two different Device structures, namely Device structure-1 (without a gate above the nano-cavity) and Device structure-2 (with a gate above the nano-cavity) based on modulation of the dielectric constant of biomolecules in the nano-cavity region. The proposed model has been validated against both numerical quantum simulation results with the help of a few fitting parameters and it also agrees with the 2-dimensional numeric simulator SILVACO TCAD used in this work. The presence/absence of biomolecules has been detected by the metric of threshold voltage sensitivity $$S_{Vth}$$ S Vth and drain current $$I_{d}$$ I d for the neutral as well as charged biomolecules. Sensitivities of partially filled nano-cavities arising out of steric hindrance in both the biosensors are compared. Optimization of device dimensions has also been included in this work to enhance the sensitivity of the biosensors. It has been witnessed that the sensitivity of the proposed biosensor is $$\sim$$ ∼ 100% higher in Device structure-1 for neutral biomolecules with dielectric constant $$\kappa$$ κ = 12, when compared to Device structure-2 for fully filled cavities. Whereas for the charged biomolecules, Device structure-1 shows $$\sim$$ ∼ 50% enhanced sensitivity than Device structure-2 for $$N_{f}=-1\times 10^{-12}$$ N f = - 1 × 10 - 12 $$\text{C}/\text{cm}^2$$ C / cm 2 . Device structure-1 demonstrates $$\sim$$ ∼ 120% higher sensitivity than Device structure-2 with partially filled cavities (i.e. 66% filled cavity). Finally, benchmarking of the proposed biosensor is presented with contemporary, state-of-the-art biosensors and it is highlighted that $$MoS_{2}$$ M o S 2 FET-based biosensor emerges with a superior sensitivity of $$S_{Vth}$$ S Vth = 0.81 V for $$\kappa = 12$$ κ = 12 .

Tweaking the Performance of Dielectric Modulated Junctionless Double Gate Metal Oxide Field Effect Transistor-Based Label-Free Biosensor

“…30 Changes in the cavity height can affect the V th of the FET. 3 The V th for the proposed device is determined using the constant current method. 31 A biosensor's threshold voltage sensitivity changes in response to alterations in the cavity height.…”

“…For instance, Biotin and APTES exhibit molecular weights in the range of approximately 220 to 240 Daltons, resulting in a volume of approximately 1 to 2 cubic nanometres (nm 3 ). In contrast, Streptavidin boasts a molecular weight of 66 kilo Daltons and occupies a volume of roughly 100 nm 3 . 32 It is noteworthy that a relevant reference experiment has employed a similar cavity height for biomolecule trapping.…”

“…The field of biosensing has gained significant attention in recent years due to its potential for revolutionizing healthcare and environmental monitoring. [1][2][3] The ability to detect and quantify biological molecules and cells in real time and with high sensitivity is crucial for various applications, including disease diagnosis, drug discovery, and environmental monitoring. 4 Due to this, developing advanced biosensors that can accurately and rapidly detect biomolecules and cells has become a key research area.…”

“…To address these challenges, researchers have proposed using dielectrically modulated (DM) FET biosensors, which offer enhanced sensitivity. 3 The demand for ultrasensitive sensors capable of detecting low concentrations of biomolecules has increased with the advancement of CMOS technology. Biosensors based on MOSFET technology have been previously documented for the highly sensitive detection of DNA, proteins, and pH levels.…”

Recent Advances in Field‐Effect Transistor‐Based Biosensors for Label‐Free Detection of SARS‐CoV‐2

“…[53,73,107] Moreover, the specificity and stability of the sensing interface composed of the bioreceptor substrate are influenced by several factors, including anti-interference, accessibility of the target molecule, steric hindrance, and the applied electric field. [108][109][110][111][112] These factors can affect the ability of a biosensor to detect a target analyte accurately and reliably. Therefore, careful consideration of these factors is essential when selecting functionalization methods and designing biosensors for specific applications.…”