背景:手性是自然界中普遍存在的现象,但对映体表现出不同的药理活性和毒理作用。因此,手性识别在生命科学等各个领域发挥着举足轻重的作用,化学合成,药物开发,和材料科学。具有明确的负载能力和有序结构的新型手性复合材料的合成对于电化学手性识别应用具有重要的潜力。然而,设计具有选择性和稳定性的电化学手性识别材料仍然是一项具有挑战性的任务。
结果:在这项工作中,利用环糊精修饰的微孔有机网络作为手性识别剂,构建了一个简单、快速的色氨酸(Trp)对映体识别的电化学传感平台。通过手性分子庚基-6-碘-6-脱氧β-环糊精和1,4-二乙炔基苯的Sonogashira-Hagihara偶联反应制备了具有手性微环境的CD-MON。BSA的附着力使CD-MON牢固地固定在电极表面,作为一种手性蛋白质,它可以通过协同作用提高手性识别能力。手性氨基酸在MON的孔传导过程中与手性微环境充分接触,由于空间位阻,L-Trp更稳定地与CD-MON/BSA结合,主客识别和氢键。因此,电化学传感器能有效识别色氨酸对映体(IL-Trp/ID-Trp=2.02),它对L-Trp的检测限为2.6μM。UV-Vis光谱证实了CD-MON对色氨酸对映体的吸附能力与电化学结果一致。
结论:制备的手性传感器具有优异的稳定性,重现性(RSD=3.7%)和选择性,实现了色氨酸外消旋体单一异构体的定量检测和实际样品的定量分析,回收率为94.0%-101.0%。这项工作代表了MON在手性电化学中的首次应用,扩展了手性传感器的应用范围,在分离科学和电化学传感中具有重要意义。
BACKGROUND: Chirality is a ubiquitous phenomenon in nature, but enantiomers exhibit different pharmacological activities and toxicological effects. Therefore, Chiral recognition plays a pivotal role in various fields such as life sciences, chemical synthesis, drug development, and materials science. The synthesis of novel chiral composites with well-defined loading capabilities and ordered structures holds significant potential for electrochemical chiral recognition applications. However, the design of selective and stable electrochemical chiral recognition materials remains a challenging task.
RESULTS: In this work, we construct a simple and rapid electrochemical sensing platform for tryptophan (Trp) enantiomer recognition using cyclodextrin-modified microporous organic network as chiral recognition agent. CD-MON with chiral microenvironment was prepared by Sonogashira-Hagihara coupling reaction of the chiral molecule heptyl-6-iodo-6-deoxyβ-cyclodextrin and 1, 4-Diethynylbenzene. The adhesion of BSA makes CD-MON firmly fixed on the electrode surface, and as a chiral protein, it can improve the chiral recognition ability through synergistic effect. Chiral amino acids are in full contact with the chiral microenvironment during pore conduction of MON, and L-Trp is more stably bound to CD-MON/BSA due to steric hindrance, host-guest recognition and hydrogen bonding. Therefore, the electrochemical sensor can effectively identify tryptophan enantiomers (IL-Trp/ID-Trp = 2.02), and it exhibits a detection limit of 2.6 μM for L-Trp. UV-Vis spectroscopy confirmed the adsorption capacity of CD-MON towards tryptophan enantiomers in agreement with electrochemistry results.
CONCLUSIONS: The prepared chiral sensor has excellent stability, reproducibility (RSD = 3.7%) and selectivity, realizes the quantitative detection of single isomer in tryptophan racemic and quantitative analysis in real samples with 94.0%-101.0% recovery. This work represents the first application of MON in chiral electrochemistry which expands the application scope of chiral sensors and holds great significance in separation science and electrochemical sensing.