Ultrasensitive terahertz microfluidic biosensor integrated with tetrahedral DNA nanostructure for specific detection of live cancer cells

• Published in: Sensors and actuators. B, Chemical Chemical, 2025-04, Vol.428, p.137252, Article 137252
• Main Authors: Shen, Peng, Ji, Yunyun, Yue, Xinmin, Li, Yifeng, Han, Mengfan, Ma, Yan, Meng, Meng, Fan, Fei, Chang, Shengjiang
• Format: Article
• Language: English
• Subjects: Bilayer-metasurface; Live cancer cells; Microfluidic; Specific detection; Terahertz biosensor; Tetrahedral DNA nanostructure
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2025.137252

Terahertz (THz) microfluidic biosensors have attracted widespread attention in the field of trace biosensing detection due to their non-destructive and harmless properties, but how to effectively achieve specific sensing of living cell samples remains a challenge. Here, a novel microfluidic biosensor consisting of bilayer orthogonal dipole resonant metasurfaces is proposed, which can realize polarization-independent electromagnetic responses and enhance the interaction between biomolecules and structures. The biosensor can achieve high-specific detection for the μL-level trace samples. More importantly, by integrating streptavidin-functionalized tetrahedral DNA nanostructures and biotinylated antibodies as recognition elements on the metasurface, the microfluidic sensor is further endowed with immune recognition properties. This method achieves high-specific trace detection of live lung cancer A549 cells through resonant frequency shifts, creating an extremely low terahertz cells detection limit record down to 1 × 103 cells/mL in the liquid environment. We first prove that tetrahedral DNA nanostructure (TDN) can improve the sensing performance compared to others. Next, the specificity of this method for detecting live lung cancer-like cells is confirmed by the control experiment with ordinary normal cells. Besides, the experiment verified the potential practicality of this method in detecting live tumor cells in complex and multi-biochemical sample environments. This work not only provides a greatly powerful diagnosis tool for live lung cancer cell measurement in the liquid environment but also offers new and reliable insights for the early-stage diagnosis of lung cancers. [Display omitted] •The tetrahedral DNA nanostructures are used for highly specific and sensitive detection of live cancer cells.•The bilayer orthogonal metasurfaces achieve polarization-independent electromagnetic responses.•A microfluidic channel constructing bilayer metasurfaces can enhance the interaction between biomolecules and structures.•The detection limit of A549 cells is down to 1 × 103 cells/mL.