高效的跨膜体系设计、制备和机制研究对细胞成像、药物递送、活性物监测等具有重要的科学意义。二硫键-细胞膜表面巯基介导的内化机制之所以至今仍知之甚少，主要的原因是由于二硫键-巯基交换反应是没有方向性的多级交换反应，最终形成复杂的多级平衡体系。而细胞膜表面不同形态巯基的存在，使这一复杂的多级平衡体系的形成成为必然，导致巯基介导的跨膜转运效率和机制研究困难重重。本项目所构建的含X取代烯烃结构单元的传感探针体系，与细胞表面巯基发生单一反应生成细胞表面捕获态的具有烯硫醚结构的跨膜主体分子，虽然该跨膜主体分子与细胞表面不同形态的巯基仍可进行单一的交换反应形成新的烯硫醚结构的跨膜分子，但反应可控且可监测，因此使相关的反应和跨膜机制研究成为可能。在此基础上，研究基于跨膜效率机制性增长的烯硫醚类新型传感体系的细胞表面巯基介导反应，开发具有实际应用价值的高效跨膜传感体系。

Studies on design and synthesis of highly efficient transmembrane systems and their transmembrane mechanism exploration are of great scientific importance to researches in the field of cell imaging, drug delivery and monitoring of active species. Mechanism of cellular uptakes mediated by thiol-disulfide exchanges on the cell surface is still illusive because of the complexity of the thiol-disulfide exchange reactions, which usually involve multi-step reactions and possess no directional property, and ultimately achieve a complex equilibrium between multiple thiol- or disulfide-containing components. Moreover, the diverse thiol-containing species on the cell surface can further complicate the exchange reactions and the multi-step equilibrium systems. This project will develop novel sensing systems using different X-substituted vinyl sulfide building blocks. Though the transmembrane host molecules will still react with cell-surface thiols through thiol-vinyl sulfide exchange reactions to form new vinyl sulfides, the unidirectional property of these exchange reactions would enable the monitoring of the complex reaction processes. Accordingly, it would be possible to explore the complex exchange reactions on the cell surface using vinyl sulfide-based sensing systems developed in this project. Furthermore, Novel sensing systems with highly efficient transmembrane capabilities and high practicability will be developed on the basis of studies on the vinyl sulfide -based sensing systems for cell-surface thiol-mediated reactions.