2D materials and van der Waals heterostructures platforms for advanced sensing of COVID-19

Effective, low-cost, reliable, and versatile diagnosing of SARS-CoV-2 is a critical factor for containing the pandemic outbreak of COVID-19. 2D materials (2DMs) have recently emerged as very promising platforms for biomedical sensors since they offer high surface area and a wide range of tunable electronic, mechanical, and optical properties. In addition, 2DMs surfaces allow adjusting the interfacial phenomena, substantial property for the tailored design of the sensing mechanism, and successful device fabrication. In this chapter, achievements in the detection of COVID-19 using platforms produced from graphene, 2DMs, and their van der Waals (vdW) heterostructures are summarized. The most important outcomes of the use of 2DMs in COVID-19 detection such as cost-effective, massive production, the possibility for device manufacture, the fabrication of point-of-care test kids, and their straightforward capacity to interconnect to the Internet of Things are characteristics expected to produce devices able to sense, record, monitor, and respond. These abilities, in synergy, might help to minimize the spread of COVID-19 and further pandemic outbreaks. © 2022 Elsevier Inc. All rights reserved.

Bipolar Junction Transistor Exhibiting Excellent Output Characteristics with a Prompt Response against the Selective Protein

Bipolar junction transistors (BJTs), the basic building blocks of integrated circuits, are deployed to control switching applications and logic operations. However, as the thickness of a conventional BJT device approaches a few atoms, its performance decreases substantially. The stacking of atomically thin 2D semiconductor materials is advantageous for manufacturing atomically thin BJT devices owing to the high carrier density of electrons and holes. Here, an atomically thin n-p-n BJT device composed of heavily doped molybdenum ditelluride (n-MoTe2) and germanium selenide (p-GeSe) sheets stacked over each other by van der Waals interactions is reported. In a common-emitter configuration, MoTe2/GeSe/MoTe2 BJT devices exhibit a considerably high current gain (beta = I-c /I-b = 29.3) at V-be = 2.5 V. The MoTe2/GeSe/MoTe2 BJT device is employed to detect streptavidin biomolecules as analytes within m. Such vdW BJT devices can trigger the development of state-of-the-art electronic devices that can be used as biosensors to detect the various kinds of target DNA and proteins like spike protein of Covid-19.