Al2O3/ZrO2 dual-dielectric Gr/CNT nanoribbon vertical tunnel FET based biosensor for genomic classification and S-protein detection in SARS-CoV-2

Abstract

The ongoing genetic mutation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) possesses the capacity to inadvertently lead to an increase in both the rates of transmission and mortality. In this study, we showcase the use of an Al2O3/ZrO2 Dual-Dielectric Gr/CNT Nanoribbon vertical tunnel field-effect transistor biosensor for the purpose of detecting spike proteins of SARS-CoV-2 in clinical samples. The proteins mentioned above are situated within the protein capsids of the virus. The effectiveness of the suggested detector has been assessed through measurements of the alteration in current drain. The present study utilizes the dielectric coefficient analogue of viral proteins as a substitute for biomolecules that exhibit internal hybridization nanogaps. The high sensitivity of the suggested detector, as evaluated on a scale ranging from 0 to 115, suggests its potential as a high-quality sensing instrument. The purpose of this study is to examine the sensitivity of DNA charge density with the aim of identifying any alterations in the virus that may impact its ability to spread and infect humans. The chromosomal composition of SARS-CoV-2 has been determined. The CMC Research Centre, situated in Vellore, Tamil Nadu, India, conducted an examination of SARS-CoV-2 samples. The scientists possess the capability to do genome sequencing on these specimens, so facilitating the examination of mutation patterns and the dispersion of different clades. A total of 250 different mutations were found out of the 600 sequences that were evaluated. The sequencing data consists of a complete collection of 250 distinct variants, including 150 missense mutations, 80 synonymous mutations, 15 mutations in noncoding regions, and 5 deletions. The comprehension of genetic variety is significantly dependent on these mutations. The proposed detector is connected to a variety of previously documented biosensors based on field-effect transistors (FETs), which are employed for the examination of genetic modifications.

Keywords: Biosensor; Charge density; Dielectric behaviour; Genomic behaviour; Mutation; SARS-CoV-2.

Fig. 1

General schematic of Covid-2 with spike protein and Nucleocapsid protein [6].

Fig. 2

SARS-CoV & SARS-CoV-2 with Anheftungsprotein Spike and host cell [13].

Fig. 3

SARS CoV-2 Spike Protein Schematic with a wide range of high-affinity Spike/ECD rabbit mAbs span the S1-ECD and the S2-ECD region of the Spike protein [14].

Fig. 4

Schematic overview of the SARS-CoV-2 Spike (S) protein and its functional domains [15].

Fig. 5

2D schematic of a Graphene channel Ge-source dual dielectric Vertical TFET (VTFET)-based bio-sensor.

Fig. 6

Detection Process of the proposed vertical TFET biosensor.

Fig. 7

a Device fabrication process: An Overview, b displays a high-resolution scanning TEM (STEM) image of the vertical TFET, demonstrating the dry transfer process's clean interface.

Fig. 7

a Device fabrication process: An Overview, b displays a high-resolution scanning TEM (STEM) image of the vertical TFET, demonstrating the dry transfer process's clean interface.

Fig. 8

Transfer properties of a label-free vertical TFET biosensor for SARS-CoV-2 detection.

Fig. 9

a& 9b. Energy distribution in the conduction and valence bands along horizontal and vertical axes for various k values and orientations.

Fig. 10

VTFET-based biosensor's drain current sensitivity for unbiased charged biomolecules, b. Time-dependent response for k = 8.46 dielectric constant.

Fig. 11

Changes in the sub-threshold swing (SS) and the ION/IOFF at different levels of k for S-protein and C-DNA.

Fig. 12

a Changes in transfer characteristics at different DNA charge densities when drain current is measured logarithmically, and b. Plot linearly.

Fig. 13

a. The transfer characteristics of a VTFET sensor for the detection of SARS-CoV-2 at a temperature of −1.9 × 10^12 C/cm2. B. The voltage at which DNA reaches its threshold (VT) in relation to concentrations of negative charge. C. The relationship between the negative charge density (Sn) of DNA and its sensitivity.

Fig. 14

a The transfer properties of a VTFET sensor at a DNA charge density of 1.9 × 10^12 C/cm2, the relationship between threshold voltage (VT) and various DNA charge densities, and the sensitivity (Sn) with respect to different DNA charge densities were investigated for the purpose of detecting SARS-CoV-2.

Fig. 15

a The relationship between trap charge density and energy, as well as the impact of trap distributions of uniform and Gaussian types on drain current characteristics.

Fig. 16

a. The spectrum density of the noise in the drain current of a TFET-based biosensor at a. f = 1 MHz b. f = 10 GHz, c. Net Sid w.r.t. frequency.

Fig. 17

a. The sensitivity of a VTFET-based biosensor is measured at k = 12. B, both with and without traps. SNR plotted against solution gate voltage, c Comparing the simulation and experimental results of the biosensor.