Coupling of plasmonic hot spots with shurikens for superchiral SERS-based enantiomer recognition.
Coupling of plasmonic hot spots with shurikens for superchiral SERS-based enantiomer recognition.
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DOI：
10.1039/d3nh00008g
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发表时间：
2022-08
影响因子：
9.7
通讯作者：
O. Guselnikova;R. Elashnikov;V. Svorcik;M. Kartau;C. Gilroy;N. Gadegaard;M. Kadodwala;A. Karimullah;O. Lyutakov
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文献类型：
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作者：
O. Guselnikova;R. Elashnikov;V. Svorcik;M. Kartau;C. Gilroy;N. Gadegaard;M. Kadodwala;A. Karimullah;O. Lyutakov
对映体的检测在药物开发以及环境和食品质量监测中是一个具有挑战性的问题，传统的光学检测方法存在信号低和灵敏度低的问题。应用表面增强拉曼散射（SERS）进行对映体识别是分析具有光学活性的有机小分子或大分子生物分子的一种有效方法。在这项工作中，我们提出了支持手性近场分布的一次性手性等离子体激元与SERS活性银纳米团簇的耦合，用于对映体选择性传感。由于等离子体耦合，观察到光学活性分析物的SERS响应有显著差异。通过数值模拟对观察结果进行了研究，并假设银粒子是由表面产生的超手性场激发的，从而在探针分子中产生额外的极化。等离子体耦合现象对水刀几何形状、银纳米结构层参数和SERS激发波长的微小变化极为敏感。设计的结构能够在几分钟内使用普通拉曼光谱仪在纳摩尔浓度范围内区分半胱氨酸对映体并探测生物分子手性。一次性等离子体衬底与特定近场极化的结合可以使SERS对映体识别成为使用标准拉曼光谱仪的常用技术。
Detection of enantiomers is a challenging problem in drug development as well as environmental and food quality monitoring where traditional optical detection methods suffer from low signals and sensitivity. Application of surface enhanced Raman scattering (SERS) for enantiomeric discrimination is a powerful approach for the analysis of optically active small organic or large biomolecules. In this work, we proposed the coupling of disposable chiral plasmonic shurikens supporting the chiral near-field distribution with SERS active silver nanoclusters for enantio-selective sensing. As a result of the plasmonic coupling, significant difference in SERS response of optically active analytes is observed. The observations are studied by numerical simulations and it is hypothesized that the silver particles are being excited by superchiral fields generated at the surface inducing additional polarizations in the probe molecules. The plasmon coupling phenomena was found to be extremely sensitive to slight variations in shuriken geometry, silver nanostructured layer parameters, and SERS excitation wavelength(s). Designed structures were able to discriminate cysteine enantiomers at concentrations in the nanomolar range and probe biomolecular chirality, using a common Raman spectrometer within several minutes. The combination of disposable plasmonic substrates with specific near-field polarization can make the SERS enantiomer discrimination a commonly available technique using standard Raman spectrometers.