Sreekanth Kandammathe Valiyaveedu, Alapan Yunus, ElKabbash Mohamed, Ilker Efe, Hinczewski Michael, Gurkan Umut A, De Luca Antonio, Strangi Giuseppe
Department of Physics, Case Western Reserve University, 10600 Euclid Avenue, Cleveland, Ohio 44106, USA.
Case Biomanufacturing and Microfabrication Laboratory, Mechanical and Aerospace Engineering Department, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Nat Mater. 2016 Jun;15(6):621-7. doi: 10.1038/nmat4609. Epub 2016 Mar 28.
Optical sensor technology offers significant opportunities in the field of medical research and clinical diagnostics, particularly for the detection of small numbers of molecules in highly diluted solutions. Several methods have been developed for this purpose, including label-free plasmonic biosensors based on metamaterials. However, the detection of lower-molecular-weight (<500 Da) biomolecules in highly diluted solutions is still a challenging issue owing to their lower polarizability. In this context, we have developed a miniaturized plasmonic biosensor platform based on a hyperbolic metamaterial that can support highly confined bulk plasmon guided modes over a broad wavelength range from visible to near infrared. By exciting these modes using a grating-coupling technique, we achieved different extreme sensitivity modes with a maximum of 30,000 nm per refractive index unit (RIU) and a record figure of merit (FOM) of 590. We report the ability of the metamaterial platform to detect ultralow-molecular-weight (244 Da) biomolecules at picomolar concentrations using a standard affinity model streptavidin-biotin.
光学传感器技术在医学研究和临床诊断领域提供了重大机遇，特别是用于检测高稀释溶液中的少量分子。为此已经开发了几种方法，包括基于超材料的无标记等离子体生物传感器。然而，由于低分子量（<500Da）生物分子的极化率较低，在高稀释溶液中检测它们仍然是一个具有挑战性的问题。在这种情况下，我们开发了一种基于双曲线超材料的小型化等离子体生物传感器平台，该平台可以在从可见光到近红外的宽波长范围内支持高度受限的体等离子体导模。通过使用光栅耦合技术激发这些模式，我们实现了不同的极端灵敏度模式，最大灵敏度为每折射率单位（RIU）30,000nm，品质因数（FOM）达到了创纪录的590。我们报告了该超材料平台使用标准亲和模型链霉亲和素 - 生物素在皮摩尔浓度下检测超低分子量（244Da）生物分子的能力。
