Hebei Key Laboratory of Applied Chemistry, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, P. R. China.
CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
Small. 2022 Feb;18(5):e2104301. doi: 10.1002/smll.202104301. Epub 2021 Nov 25.
The fabrication of discrete nanostructures with both plasmonic circular dichroism (PCD) and chiral features is still a challenge. Here, gold nanoarrows (GNAs) with both chiroptical responses and chiral morphologies are achieved by using L-selenocystine (L-SeCys ) as a chiral inducer. While L-SeCys generates GNAs with a weak PCD signal, the irradiated L-SeCys (irr-L-SeCys ) leads to GNAs with featured helical grooves (HeliGNAs) accompanying with a strong PCD signal. It is revealed that when L-SeCys is photo-irradiated, the emergence of selenyl radicals plays an important role in the formation of HeliGNAs and enhancement of the chiroptical signal. In comparison with L-SeCys and the other kinds of sulfur-containing amino acids, the formation mechanism of helical grooves on the surface of GNAs is proposed. Both HeliGNAs and GNAs are used to discriminate amino acids by utilizing surface enhanced Raman scattering (SERS) effect. In the presence of either GNAs or HeliGNAs as the substrate, Fmoc-L-Phe shows more significant SERS than Fmoc-D-Phe. This study may advance the design of discrete plasmonic nanomaterials with both chiral morphology and potential applications in discrimination of chiral molecules.
具有圆二色性（PCD）和手性特征的离散纳米结构的制造仍然是一个挑战。在这里，使用 L-硒代半胱氨酸（L-SeCys）作为手性诱导剂，实现了具有手性响应和手性形态的金纳米箭（GNA）。虽然 L-SeCys 产生具有弱 PCD 信号的 GNA，但辐照的 L-SeCys（irr-L-SeCys）导致具有特征螺旋凹槽（HeliGNA）的 GNA 伴随着强 PCD 信号。结果表明，当 L-SeCys 被光辐照时，硒基自由基的出现在手性 GNA 的形成和手性信号的增强中起着重要作用。与 L-SeCys 和其他含硫氨基酸相比，提出了在 GNA 表面形成螺旋凹槽的机制。使用表面增强拉曼散射（SERS）效应，HeliGNA 和 GNA 都可用于区分氨基酸。在存在 GNA 或 HeliGNA 作为底物的情况下，Fmoc-L-Phe 比 Fmoc-D-Phe 显示出更显著的 SERS。这项研究可能会推进具有手性形态和在手性分子识别中潜在应用的离散等离子体纳米材料的设计。
