通过双链DNA辅助构象固定化的手性分子印迹传感器用于对映体中D-肉碱的高选择性测定。

Chiral molecular imprinted sensor for highly selective determination of D-carnitine in enantiomers via dsDNA-assisted conformation immobilization.

作者信息

Zhang Lianming, Luo Kui, Li Dan, Zhang Yufu, Zeng Ying, Li Jianping

机构信息

Guangxi Colleges and Universities Key Laboratory of Food Safety and Detection, Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541004, PR China; College of Material and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu, 610000, PR China.

出版信息

Anal Chim Acta. 2020 Nov 1;1136:82-90. doi: 10.1016/j.aca.2020.08.046. Epub 2020 Aug 27.

DOI:10.1016/j.aca.2020.08.046

PMID:33081952

Abstract

In this paper, a novel approach was established on the basis of a molecularly imprinted technique with the aid of double-stranded deoxyribonucleic acid (dsDNA) embedded in a molecularly imprinted polymer (MIP) membrane as a new functional unit with chiral recognition for highly specific chiral recognition. The chiral molecules were immobilized and anchored in the cavities of the MIP membrane on the basis of the three-dimensional structure of a molecule determined by the functional groups, spatial characterization of the cavities of MIPs, and the spatial orientation with dsDNA embedded in MIPs. D-carnitine was selected as an example of a chiral molecular template, which intercalated into dsDNA immobilized on the gold electrode surface to form dsDNA-D-carnitine complex, and then the complex was embedded in the MIP during electropolymerization. After elution, the stereo-selective cavities were obtained. Our findings have shown that AAAA-TTTT base sequence had high affinity for D-carnitine intercalation. Combined with the electrochemical detection method, MIP sensor was prepared. The selectivity of the MIP sensor to ultratrace D-carnitine was significantly improved; the sensor had remarkable stereo-selectivity and highly chiral specific recognition to D-carnitine, and L-carnitine with a concentration of 10,000 times D-carnitine did not interfere with the detection of D-carnitine in the assay of raceme. The sensor also exhibited high sensitivity to ultratrace D-carnitine determination with a linear response to the concentration of D-carnitine in the range of 3.0 × 10 mol/L to 4.0 × 10 mol/L, with a detection limit of 2.24 × 10 mol/L. The mechanism of chiral recognition was studied, and result showed that apart from the recognition effect of imprinted cavities, dsDNA provided chiral selectivity to the spatial orientation of chiral molecules via the intercalation of chiral molecules with dsDNA and electrostatic interaction with groups of DNA base.

摘要

本文基于分子印迹技术建立了一种新方法，借助嵌入分子印迹聚合物（MIP）膜中的双链脱氧核糖核酸（dsDNA）作为具有手性识别功能的新功能单元，实现高度特异性的手性识别。基于由官能团确定的分子三维结构、MIPs空穴的空间特征以及嵌入MIPs中的dsDNA的空间取向，手性分子被固定并锚定在MIP膜的空穴中。选择D-肉碱作为手性分子模板的示例，其插入固定在金电极表面的dsDNA中形成dsDNA-D-肉碱复合物，然后在电聚合过程中将该复合物嵌入MIP中。洗脱后，获得立体选择性空穴。我们的研究结果表明，AAAA-TTTT碱基序列对D-肉碱插入具有高亲和力。结合电化学检测方法，制备了MIP传感器。MIP传感器对超痕量D-肉碱的选择性显著提高；该传感器对D-肉碱具有显著的立体选择性和高度手性特异性识别，在消旋体测定中，浓度为D-肉碱10000倍的L-肉碱不干扰D-肉碱的检测。该传感器对超痕量D-肉碱测定也表现出高灵敏度，对D-肉碱浓度在3.0×10⁻⁹mol/L至4.0×10⁻⁷mol/L范围内呈线性响应，检测限为2.24×10⁻¹⁰mol/L。对手性识别机制进行了研究，结果表明，除了印迹空穴的识别作用外，dsDNA通过手性分子与dsDNA的插入以及与DNA碱基基团的静电相互作用，为手性分子的空间取向提供了手性选择性。