College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, China.
Mikrochim Acta. 2020 Nov 3;187(11):636. doi: 10.1007/s00604-020-04606-y.
A novel chiral sensing platform, 6-O-α-maltosyl-β-cyclodextrin (Mal-βCD)-based film, is proposed for selective electrochemical recognition of tyrosine (Tyr) enantiomers. Black phosphorus nanosheets (BP NSs) and Mal-βCD modified glassy carbon electrode (Mal-βCD/BP NSs/GCE) were prepared by a layer-to-layer drop-casting method, and the platform was easy to fabricate and facile to operate. It is proposed that the amino and hydroxyl groups of the Tyr enantiomers and the chiral hydroxyl groups of Mal-βCD selectively form intermolecular hydrogen bonds to dominate effective chiral recognition. Two linear equations of Ip (μA) = 11.40 C (mM) + 0.28 (R = 0.99147) and Ip (μA) = 7.96 C (mM) + 0.22 (R = 0.99583) in the concentration range 0.01-1.00 mM have been obtained. The limits of detection (S/N=3) for L-Tyr and D-Tyr were 4.81 and 6.89 µM, respectively. An interesting phenomenon was that the value of I/I (1.51) in this work was slightly higher than the value of I/I (1.49) reported in our previous study, where tryptophan (Trp) enantiomers were electrochemically recognized by Nafion (NF)-stabilized BPNSs-G2-β-CD composite. The two similar sensors fabricated by different methods showed different recognition ability toward either Tyr or Trp enantiomers, and the underlying mechanism was discussed in detail. More importantly, the proposed chiral sensor enables prediction of the percentages of D-Tyr in racemic Tyr mixtures. The chiral sensor may provide a novel approach for the fabrication of novel chiral platforms in the practical detection of L- or D-enantiomer in racemic Tyr mixtures.Graphical abstract.
一种新型手性传感平台,基于 6-O-α-麦芽寡糖基-β-环糊精(Mal-βCD)的薄膜,用于选择性电化学识别酪氨酸(Tyr)对映体。通过层层滴铸法制备了黑磷纳米片(BP NSs)和 Mal-βCD 修饰的玻碳电极(Mal-βCD/BP NSs/GCE),该平台易于制造且易于操作。提出的 Tyr 对映体的氨基和羟基以及 Mal-βCD 的手性羟基选择性地形成分子间氢键,以主导有效的手性识别。在 0.01-1.00 mM 的浓度范围内,获得了 Ip(μA)=11.40 C(mM)+0.28(R=0.99147)和 Ip(μA)=7.96 C(mM)+0.22(R=0.99583)的两个线性方程。对于 L-Tyr 和 D-Tyr,检测限(S/N=3)分别为 4.81 和 6.89 μM。一个有趣的现象是,在这项工作中,I/I(1.51)的值略高于我们之前研究中报道的 Nafion(NF)稳定的 BPNSs-G2-β-CD 复合材料电化学识别色氨酸(Trp)对映体时的 I/I(1.49)的值。两种由不同方法制备的类似传感器对 Tyr 或 Trp 对映体表现出不同的识别能力,详细讨论了其潜在机制。更重要的是,所提出的手性传感器可以预测外消旋 Tyr 混合物中 D-Tyr 的百分比。该手性传感器可以为在实际检测外消旋 Tyr 混合物中的 L 或 D-对映体时构建新型手性平台提供一种新方法。