WTe2 Weyl semimetal conical microarray enabled quantum-enhanced terahertz photocurrent sensing for organophosphorus toxin detection in simulated body fluid
- 1College of Criminal Science and Technology, Jilin Police College, Changchun, China
- 2School of Physics, Changchun University of Science and Technology, Changchun, China
Abstract
As a representative topological quantum system, type-II Weyl semimetals break the fundamental bandgap limitation of conventional semiconductor photodetectors and deliver giant intrinsic nonlinear optical response originating from topologically protected Weyl points and Fermi arc surface states, providing a disruptive material platform for advanced room-temperature terahertz (THz) optoelectronics. Building on this quantum material advantage, we develop a room-temperature THz sensor based on a periodic WTe2 conical microarray for quantitative detection of the organophosphorus neurotoxin chlorpyrifos in simulated body fluid (SBF). Each microcone measures 80 µm in base diameter and 60 µm in height, arranged with a 100 µm center-to-center pitch on a Si/SiO2 substrate with Au/Ti electrodes. A 140 GHz continuous-wave THz source illuminates the chip from above, and the photocurrent is read out by a Keithley 2400 digital source meter via two tungsten-carbide microprobes. Leveraging the geometric near-field concentration effect at the cone tips, the proposed architecture synergistically enhances the second-order nonlinear photocurrent rectification originating from the Weyl-point band structure of WTe2, as confirmed by CST electromagnetic simulation. The underlying sensing mechanism relies on chlorpyrifos-induced dielectric screening and interfacial charge transfer at the WTe2 surface, which modulate the THz-to-DC rectification efficiency. Current responsivity (Ra) and noise-equivalent power (NEP) are extracted from illuminated and dark current–voltage (I–V) characteristics as a function of chlorpyrifos concentration over a bias range of 7.0–8.0 V. The sensor achieves a limit of detection (LOD) of 12 ng/mL across a dynamic range of 0.05–100 µg/mL in 0.7% saline SBF, with a logarithmic calibration fit of R2 = 0.991. Compared with conventional semiconductor and thermal THz detectors, the topological-quantum-material device realizes room-temperature high-sensitivity detection without relying on interband transition or cryogenic cooling, demonstrating fundamentally superior performance stability and broadband adaptability. This work demonstrates that microstructured Weyl semimetal heterostructures enable quantum-enhanced THz biochemical sensing, providing a new device architecture for label-free, reagent-free toxin detection in complex aqueous environments.
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BibTeX
@article{zhang2026wte2,
title = {{WTe2 Weyl semimetal conical microarray enabled quantum-enhanced terahertz photocurrent sensing for organophosphorus toxin detection in simulated body fluid}},
author = {Xu Zhang and Mingxin Li and Chunting Wu},
journal = {Frontiers in Physiology},
year = {2026},
month = oct,
doi = {10.3389/fphys.2026.1997758},
url = {https://doi.org/10.3389/fphys.2026.1997758},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - WTe2 Weyl semimetal conical microarray enabled quantum-enhanced terahertz photocurrent sensing for organophosphorus toxin detection in simulated body fluid
AU - Xu Zhang
AU - Mingxin Li
AU - Chunting Wu
PY - 2026
DA - 2026/10/13
JO - Frontiers in Physiology
DO - 10.3389/fphys.2026.1997758
UR - https://doi.org/10.3389/fphys.2026.1997758
AB - As a representative topological quantum system, type-II Weyl semimetals break the fundamental bandgap limitation of conventional semiconductor photodetectors and deliver giant intrinsic nonlinear optical response originating from topologically protected Weyl points and Fermi arc surface states, providing a disruptive material platform for advanced room-temperature terahertz (THz) optoelectronics. Building on this quantum material advantage, we develop a room-temperature THz sensor based on a periodic WTe2 conical microarray for quantitative detection of the organophosphorus neurotoxin chlorpyrifos in simulated body fluid (SBF). Each microcone measures 80 µm in base diameter and 60 µm in height, arranged with a 100 µm center-to-center pitch on a Si/SiO2 substrate with Au/Ti electrodes. A 140 GHz continuous-wave THz source illuminates the chip from above, and the photocurrent is read out by a Keithley 2400 digital source meter via two tungsten-carbide microprobes. Leveraging the geometric near-field concentration effect at the cone tips, the proposed architecture synergistically enhances the second-order nonlinear photocurrent rectification originating from the Weyl-point band structure of WTe2, as confirmed by CST electromagnetic simulation. The underlying sensing mechanism relies on chlorpyrifos-induced dielectric screening and interfacial charge transfer at the WTe2 surface, which modulate the THz-to-DC rectification efficiency. Current responsivity (Ra) and noise-equivalent power (NEP) are extracted from illuminated and dark current–voltage (I–V) characteristics as a function of chlorpyrifos concentration over a bias range of 7.0–8.0 V. The sensor achieves a limit of detection (LOD) of 12 ng/mL across a dynamic range of 0.05–100 µg/mL in 0.7% saline SBF, with a logarithmic calibration fit of R2 = 0.991. Compared with conventional semiconductor and thermal THz detectors, the topological-quantum-material device realizes room-temperature high-sensitivity detection without relying on interband transition or cryogenic cooling, demonstrating fundamentally superior performance stability and broadband adaptability. This work demonstrates that microstructured Weyl semimetal heterostructures enable quantum-enhanced THz biochemical sensing, providing a new device architecture for label-free, reagent-free toxin detection in complex aqueous environments.
SN - 1664-042X
ER -