Ignatyeva Daria O, Knyazev Grigory A, Kapralov Pavel O, Dietler Giovanni, Sekatskii Sergey K, Belotelov Vladimir I
Lomonosov Moscow State University, Faculty of Physics, Leninskie Gory, 119991, Moscow, Russia.
Russian Quantum Center, Novaya str., 143025, Skolkovo, Moscow, Russia.
Sci Rep. 2016 Jun 16;6:28077. doi: 10.1038/srep28077.
Currently, sensors invade into our everyday life to bring higher life standards, excellent medical diagnostic and efficient security. Plasmonic biosensors demonstrate an outstanding performance ranking themselves among best candidates for different applications. However, their sensitivity is still limited that prevents further expansion. Here we present a novel concept of magnetoplasmonic sensor with ultranarrow resonances and high sensitivity. Our approach is based on the combination of a specially designed one-dimensional photonic crystal and a ferromagnetic layer to realize ultralong-range propagating magnetoplasmons and to detect alteration of the environment refractive index via observation of the modifications in the Transversal Magnetooptical Kerr Effect spectrum. The fabrication of such a structure is relatively easy in comparison with e.g. nanopatterned samples. The fabricated heterostructure shows extremely sharp (angular width of 0.06°) surface plasmon resonance and even sharper magnetoplasmonic resonance (angular width is 0.02°). It corresponds to the propagation length as large as 106 μm which is record for magnetoplasmons and promising for magneto-optical interferometry and plasmonic circuitry as well as magnetic field sensing. The magnitude of the Kerr effect of 11% is achieved which allows for detection limit of 1∙10(-6). The prospects of further increase of the sensitivity of this approach are discussed.
当前，传感器已融入我们的日常生活，带来了更高的生活标准、出色的医学诊断和高效的安全保障。表面等离子体激元生物传感器表现卓越，在不同应用的最佳候选者中名列前茅。然而，其灵敏度仍然有限，这阻碍了其进一步发展。在此，我们提出了一种具有超窄共振和高灵敏度的磁等离子体传感器的新概念。我们的方法基于将特殊设计的一维光子晶体与铁磁层相结合，以实现超长程传播的磁等离子体激元，并通过观察横向磁光克尔效应光谱的变化来检测环境折射率的改变。与例如纳米图案化样品相比，这种结构的制造相对容易。所制备的异质结构显示出极其尖锐的（角宽度为0.06°）表面等离子体共振，甚至更尖锐的磁等离子体激元共振（角宽度为0.02°）。这对应于高达106μm的传播长度，这对于磁等离子体激元来说是创纪录的，并且对于磁光干涉测量、等离子体电路以及磁场传感都很有前景。实现了11%的克尔效应幅度，这使得检测限达到1∙10(-6)。本文还讨论了进一步提高该方法灵敏度的前景。
