Integrated Terahertz Metasensor Identifies and Quantifies Multiple Biomolecules in Complex Mixtures

Researchers in China and Australia have developed an on-chip terahertz metasensor that integrates terahertz generation, analyte interaction, and signal detection onto a single platform to identify and quantify multiple components within complex biomolecular mixtures. Reported in Light: Science & Applications, the self-supporting chip-scale system establishes a new approach for resolving multi-component molecular signatures without chemical labels or sample destruction.

Conventional terahertz spectroscopy identifies chemical substances by probing their distinct fingerprint absorption features in the terahertz frequency band in a nondestructive, label-free manner. However, existing laboratory spectroscopy platforms remain bulky and highly susceptible to ambient environmental disturbances, while previously reported on-chip sensors have focused predominantly on qualitative measurements of single target analytes rather than complex samples.

The research collaboration was led by Professor Qiang Wu, Associate Professor Yao Lu, and Professor Jingjun Xu from Nankai University, working alongside Professor Baohua Jia from RMIT University. Their device consolidates broadband terahertz wave generation, propagation, analyte interaction, and signal detection on a single lithium niobate wafer, moving terahertz fingerprint sensing toward compact and portable operational platforms.

First author Xitan Xu outlined three primary design objectives guiding the development of the metasensor: integrating essential terahertz functional modules onto a unified chip platform, strengthening broadband interactions between terahertz radiation and target analytes, and quantitatively resolving the spectral contributions of individual chemical components in mixed solutions.

To realize these capabilities, the device couples a self-supporting lithium niobate wafer with an engineered periodic metasurface array. The lithium niobate substrate functions as the medium for generating, guiding, and detecting terahertz signals, while the metasurface converts the guided wave into a surface-confined spoof surface plasmon polariton mode. This surface confinement concentrates the broadband electromagnetic fields along the sensing interface, significantly extending the effective interaction path with deposited analytes.

In laboratory demonstrations, the researchers evaluated the platform using four representative biomolecules comprising two amino acids and two disaccharides. The analytes were deposited directly onto the metasensor via drop-casting and allowed to dry. The device identified each individual substance by its characteristic terahertz absorption fingerprint and, when multiple biomolecules were combined into a mixture, successfully resolved their individual contributions through spectral decomposition algorithms.

The study authors forecast that integrating this on-chip metasensor architecture with compact optical modules, microfluidic sample-handling systems, and advanced data-processing algorithms could enable next-generation analytical instruments for point-of-use precision healthcare, pharmaceutical manufacturing, and continuous biochemical process monitoring.

Subject of Research: On-chip terahertz metasensor for quantitative multi-component biomolecular analysis

Article Title: On-chip terahertz metasensor for quantitative multi-component biomolecular identification

Article References: On-chip terahertz metasensor for quantitative multi-component biomolecular identification. Original publication (Bibliographic details unavailable.)

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DOI: Not provided

Keywords: terahertz spectroscopy, metasensors, biomolecular identification, lithium niobate, spectral decomposition, biosensing, integrated optics, On-chip, terahertz, metasensor, quantitative, multi-component