Terahertz SWNT-based fluidic chip for sensing enantioselectivity

• Published in: Carbon (New York) 2024-05, Vol.225, p.119116, Article 119116
• Main Authors: Yin, Jifan, Chang, Han, Geng, Wenhui, Xie, Lijuan
• Format: Article
• Language: English
• Subjects: Chiral molecules; Enantioselectivity; Single-walled carbon nanotube; Terahertz
• ISSN: 0008-6223
• DOI: 10.1016/j.carbon.2024.119116

Enantioselectivity sensing is crucial in biological systems due to the impact of the selective behaviors of chiral compounds on their targets. Conventional approaches for detecting enantioselectivity are restricted by the presence of high phonon energy, complex device manufacturing processes, low sensitivity, and the need for large sample sizes. Here, we propose a single-walled carbon nanotube (SWNT)-based fluidic chip that uses terahertz (THz) optical rotatory dispersion (ORD) spectroscopy to detect tartaric acids with high selectivity in very small amounts of liquid. The chip is composed of tailored U-shaped metasurfaces that show significant amplification of the near-field around the typical peaks of tartaric acids in the ORD spectrum. Additionally, it includes subwavelength gratings made of SWNTs, allowing for accurate detection of polarization angles. The limit of detection (LOD) for d-tartaric acid and l-tartaric acid are 17.9 mg/L and 11.0 mg/L, respectively. The sensitivities are superior to those of UV ORD or CD spectrometers. Furthermore, the presence of tartaric acid in wine is effectively identified, with a LOD of 25.60 mg/L. This technological development provides a significant improvement in chiral analysis by allowing for quick, highly sensitive, and precise detection of enantiomers. Schematic illustration of biosensing based on the proposed SWNT-based fluidic chips. [Display omitted]