Beijing Engineering Research Center for Mixed Reality and Advanced Display, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China.
ACS Appl Mater Interfaces. 2024 Mar 27;16(12):15193-15201. doi: 10.1021/acsami.3c18947. Epub 2024 Mar 16.
Chiral metasurfaces are capable of generating a huge superchiral field, which has great potential in optoelectronics and biosensing. However, the conventional fabrication process suffers greatly from time consumption, high cost, and difficult multilayer alignment, which hinder its commercial application. Herein, we propose a twisted stacking carbon-based terahertz (THz) chiral metasurface (TCM) based on laser-induced graphene (LIG) technology. By repeating a two-step process of sticking a polyimide film, followed by laser direct writing, the two layers of the TCM are aligned automatically in the fabrication. Laser manufacturing also brings such high processing speed that a TCM with a size of 15 × 15 mm can be prepared in 60 s. In addition, due to the greater dissipation of LIG than that of metals in the THz band, a giant circular dichroism (CD) of +99.5 to -99.6% is experimentally realized. The THz biosensing of bovine serum albumin enhanced by the proposed TCMs is then demonstrated. A wide sensing range (0.5-50 mg mL) and a good sensitivity [ΔCD: 2.09% (mg mL), Δ: 0.0034 THz (mg mL)] are proved. This LIG-based TCM provides an environment-friendly platform for chiral research and has great application potential in rapid and low-cost commercial biosensing.
手性超表面能够产生巨大的超手性场，在手性光学和生物传感等领域具有很大的应用潜力。然而，传统的制造工艺受到耗时、高成本和多层对准困难的限制，阻碍了其商业化应用。在此，我们提出了一种基于激光诱导石墨烯（LIG）技术的扭曲堆叠碳基太赫兹（THz）手性超表面（TCM）。通过重复粘贴聚酰亚胺薄膜和激光直写的两步工艺，在制造过程中可以自动对准 TCM 的两层。激光制造还具有如此高的加工速度，以至于可以在 60 秒内制备出 15×15mm 的 TCM。此外，由于 LIG 在太赫兹波段的耗散大于金属，因此实验实现了+99.5%至-99.6%的巨大圆二色性（CD）。然后，演示了所提出的 TCM 增强的牛血清白蛋白的太赫兹生物传感。证明了宽的传感范围（0.5-50mgmL）和良好的灵敏度[ΔCD：2.09%（mgmL），Δ：0.0034THz（mgmL）]。这种基于 LIG 的 TCM 为手性研究提供了一个环保的平台，在手性光学和生物传感等领域具有很大的应用潜力。
