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Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor
Published on: August 30, 2012
Terahertz Sensor for Trace Pb2+ in Liquid Based on Weyl Semimetal Films with External Field Modulation.
Shouwa Liu1, Wenhao Xu1, Wenzhe Wang1
1School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, China.
ACS Applied Materials & Interfaces
|July 6, 2026
Summary
A novel terahertz sensor detects trace lead ions (Pb2+) without direct contact. This breakthrough offers ultrasensitive, rapid environmental monitoring for public health protection.
Area of Science:
- Quantum Materials Science
- Terahertz Optoelectronics
- Environmental Sensing Technology
Background:
- Detecting trace lead ions (Pb2+) in liquids is crucial for environmental monitoring and public health.
- Conventional methods for lead detection are often complex, require direct contact, or use bulky equipment, limiting practical application.
- Nondirect contact, ultrasensitive detection methods are needed for real-time environmental analysis.
Purpose of the Study:
- To develop a novel, label-free terahertz (THz) sensor for rapid and ultrasensitive detection of trace lead ions (Pb2+) in liquid environments.
- To investigate the use of Weyl semimetal (WSM) thin films in a THz sensor for enhanced lead ion detection.
- To explore auxiliary modulation strategies to improve sensor performance, including signal-to-noise ratio and sensitivity.
Main Methods:
- Fabrication of Weyl semimetal (WSM) thin films using magnetron sputtering.
- Integration of WSM films with an interdigitated electrode structure to create a terahertz (THz) sensor operating at 0.1 THz.
- Utilizing modulation of THz conductivity in WSMs due to adsorbed Pb2+, enhanced by laser illumination and acoustic excitation.
Main Results:
- The developed THz sensor achieved a limit of detection of 6.0 ng/L for Pb2+ in liquid samples.
- The sensor demonstrated a linear concentration response relationship for lead ions.
- Auxiliary modulation strategies significantly improved the signal-to-noise ratio and reduced noise-equivalent power (NEP), enhancing detection sensitivity.
Conclusions:
- The study presents a feasible sensing framework integrating topological quantum materials and THz optoelectronics for trace heavy metal quantification.
- The developed WSM-based THz sensor offers a practical route for real-time field environmental monitoring and liquid trace heavy metal analysis.
- This approach overcomes limitations of conventional techniques, enabling nondirect contact and ultrasensitive lead ion detection.
