Ultrasensitive Detection of SARS‐CoV‑2 by Flexible Metal Oxide Field‐Effect Transistors

Abstract

The pandemic of coronavirus disease 2019 (COVID‐19) reflects the great significance of rapid and accurate detection of pathogens by new sensing technologies. Antibody based biosensors with high sensitivity comparable to golden standard polymerase chain reaction (PCR) and miniaturized device features allow the detection of pathogens in portable and flexible formats. Herein, flexible metal oxide electrolyte‐gated field‐effect transistors (EGFETs) are reported to serve as the biosensors for rapid and ultrasensitive severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) detection. The semiconducting layer of the EGFETs associates with hybrid material of PEI doped metal oxides that not only improves the transistor performance, but also regulates microstructure forming higher surface‐to‐volume ratio, which brings more antibodies immobilization, resulting in higher sensitive, and faster response for detecting SARS‐CoV‐2. Comprehensive studies of materials and interfacing engineering of the EGFETs not only build the strong foundation for the EGFET sensors to show excellent sensitivity with a limit of detection from 0.14 fg ml−1 for SARS‐CoV‐2 S1 proteins, and 0.09 copies µl−1 for SARS‐CoV‐2 viruses, but also offer good mechanical properties to enable thin, soft flexible sensing platforms. This work provides a new strategy from materials to devices as innovative schemes for virus/pathogens detection.

Probing Hyperbolic Shear Polaritons in β‐Ga2O3 Nanostructures Using STEM‐EELS

“…[9,10] Additionally, as an anisotropic material, 𝛽-Ga 2 O 3 can sustain phonon polaritons along different directions over a wide spectral range according to theoretical predictions, [6,34] which is desirable for nanophotonic applications. Thanks to the recent development of electron energy loss spectroscopy (EELS) with support from scanning transmission electron microscopy (STEM), an electron probe with atomic spatial resolution and a sub-10 meV energy resolution, as well as an extremely wide spectral range (from ≈20 meV to 3 keV) can be achieved, [35][36][37][38][39][40][41] making it possible to study the HShP modes of 𝛽-Ga 2 O 3 in a diversity of nanostructures.…”

Asymmetric Schottky Barrier-Generated MoS2/WTe2 FET Biosensor Based on a Rectified Signal

“…These "absolute value signals" directly collect and process the specific changes in biomolecules. Although these signals carry the biomolecules' charge information [8][9][10], they have the drawbacks of incomplete, unstable, and unreliable detection. Kulkarni et al reported that the detection range of FET-based biosensors was limited by the Debye length due to the Debye screening effect.…”