Active Control and Sensing Application of Ultra-Narrowband Circular Dichroism in Multilayer Chiral Nanorod Arrays
Active Control and Sensing Application of Ultra-Narrowband Circular Dichroism in Multilayer Chiral Nanorod Arrays
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DOI：
10.1021/acsami.3c07828
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发表时间：
2023-09-14
影响因子：
9.5
通讯作者：
Zhang，Pin
中科院分区：
文献类型：
--
作者：
Wang，Yongkai;Peng，Yu;Zhang，Pin
窄带圆二色性（CD）因其在检测手性分子和催化方面的高灵敏度而受到广泛关注。然而，设计具有优异传感性能、可动态调节的手性超表面仍然面临挑战。本文将电可调材料铌酸锂和分布式布拉格反射器引入手性纳米棒结构中，形成多层手性纳米棒阵列（MCNA）。仿真结果表明，MCNA 可以在可见光谱中产生四个强的超窄带 (UNB) CD 信号。 UNB CD信号强度高达0.86，最小半峰全宽(FWHM)高达0.21 nm。 MCNA的表面电场和电流分布表明，四个UNB CD信号主要源自手性纳米棒层中的xandy方向Tamm共振。铌酸锂的折射率可以通过改变电场来调节，从而可以主动调节UNB CD信号。此外，还分析了MCNA在SARS-CoV-2溶液中的传感性能，其品质因数（FOM）可以达到惊人的2092。这些发现不仅有助于UNB手性器件的设计，而且为环境监测和手性分子的超灵敏检测提供了新的可能性。
Narrowband circular dichroism (CD) has attracted wide attention for its high sensitivity in detecting chiral molecules and catalysis. However, designing a chiral metasurface with excellent sensing performance that can be dynamically tuned still poses challenges. This paper introduces lithium niobate, an electrically tunable material, and a distributed Bragg reflector into chiral nanorod structures to form multilayer chiral nanorod arrays (MCNAs). Simulation results show that MCNAs can generate four strong ultra-narrowband (UNB) CD signals in the visible light spectrum. The UNB CD signal intensity was up to 0.86, and the minimum full width at half-maximum (FWHM) was up to 0.21 nm. The surface electric field and current distribution of MCNAs indicate that the four UNB CD signals mainly originate from thexandydirection Tamm resonances in the chiral nanorod layer. The refractive index of lithium niobate can be tuned by changing the electric field, allowing the active tuning of UNB CD signals. In addition, the sensing performance of MCNAs in the SARS-CoV-2 solution was analyzed, and the figure of merit (FOM) can reach an astonishing 2092. These findings not only assist with the design of UNB chiral devices but also offer new possibilities for the environmental monitoring and ultrasensitive detection of chiral molecules.