AbstractAn electrochemical chiral multilayer nanocomposite was prepared by modifying a glassy carbon electrode (GCE) via opposite-charge adsorption of amino-modified β-cyclodextrin (NH2-β-CD), gold-platinum core-shell microspheres (Au@Pts), polyethyleneimine (PEI), and multi-walled carbon nanotubes (MWCNTs). The modified GCE was applied to the enantioselective voltammetric determination of tryprophan (Trp). The Au@Pts enable an effective immobilization of the chiral selector (NH2-β-CD) and enhance the electrochemical performance. Scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, FTIR and electrochemical methods were used to characterize the nanocomposite. Trp enantiomers were then determined by differential pulse voltammetry (DPV) (with a peak potential of +0.7 V vs. Ag/AgCl). The recognition efficiency was expressed by an increase in peak height by about 32% for DPV determinations of L-Trp compared to D-Trp in case of a 5 mM Trp solution of pH 7.0. Response was linear in the 10 μM to 5.0 mM concentration range, and the limits of detection were 4.3 μM and 5.6 μM with electrochemical sensitivity of 43.5 μA·μM−1·cm−2 and 34.6 μA·μM−1·cm−2 for L-Trp and D-Trp, respectively (at S/N = 3). Graphical AbstractSchematic of an electrochemical chiral multilayer nanocomposite composed of multi-walled carbon nanotubes (MWCNTs), polyethyleneimine (PEI), gold-platinum core-shell microspheres (Au@Pt) and amino-modified β-cyclodextrin (NH2-β-CD). It was prepared by modifying a glassy carbon electrode (GCE) for enantioselective voltammetric determination of tryptophan (Trp) enantiomers.

中文翻译：

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使用以氨基修饰的β-环糊精为识别元件的多层纳米复合材料对色氨酸的伏安手性鉴别

摘要 通过氨基修饰的β-环糊精（NH2-β-CD）、金铂核壳微球（Au@Pts）、聚乙烯亚胺的反电荷吸附对玻碳电极（GCE）进行改性，制备了电化学手性多层纳米复合材料。 (PEI) 和多壁碳纳米管 (MWCNT)。将改进的 GCE 应用于色氨酸 (Trp) 的对映选择性伏安法测定。Au@Pts 能够有效固定手性选择剂（NH2-β-CD）并提高电化学性能。使用扫描电子显微镜、透射电子显微镜、紫外-可见光谱、FTIR 和电化学方法来表征纳米复合材料。然后通过差分脉冲伏安法 (DPV)（峰值电位为 +0.7 V vs. Ag/AgCl）测定 Trp 对映异构体。在 5 mM Trp 溶液的 pH 值 7.0 的情况下，与 D-Trp 相比，L-Trp 的 DPV 测定的峰高增加了约 32%，表示识别效率。响应在 10 μM 至 5.0 mM 浓度范围内呈线性，检测限分别为 4.3 μM 和 5.6 μM，电化学灵敏度分别为 43.5 μA·μM-1·cm-2 和 34.6 μA·μM-1·cm-2 L-Trp 和 D-Trp，分别（在 S/N = 3）。图解摘要由多壁碳纳米管（MWCNTs）、聚乙烯亚胺（PEI）、金铂核壳微球（Au@Pt）和氨基修饰的β-环糊精（NH2-β-CD）组成的电化学手性多层纳米复合材料示意图. 它是通过修改玻碳电极 (GCE) 制备的，用于对映选择性伏安法测定色氨酸 (Trp) 对映异构体。