Sensory Lipid Membrane Films with Integrated Inorganic Coordination Complexes

纯水中阴离子的检测和识别是超分子化学中的一个重要挑战，至今仍是一个相对未发展的研究领域。这是由于与感测阴离子相关的基本挑战，归因于它们与周围水分子的强关联（高溶剂化能），需要被打破以结合到受体。这些受体通常在水中溶解度低，对目标阴离子的选择性差，对结合位点的弱阴离子亲和力加剧了这种情况。无机磷酸盐作为生物系统中的化学构建块无处不在，例如存在于大多数代谢反应中。它也与环境高度相关，农业中化肥使用量的增加导致水道中磷酸盐过量。这导致了富营养化，其影响可以在有害藻类大量繁殖和水生生物缺氧的“死亡区”中看到。检测磷酸盐水平的常用技术从使用传统的分子荧光探针和光学分析到NMR滴定技术。然而，这些基于实验室的方法通常是昂贵的，耗时和费力的。相比之下，电化学传感器便携、便宜并且可以在现场用于连续监测。阴离子受体的结合环境可以被有效地工程化以促进受体和靶向阴离子之间的高亲和力或强结合。感官膜表现出可测量的结合增强因子，其中溶剂化效应受到控制。控制这种效应的一种实际方法是通过使用这样的膜，其提供调节界面介电微环境的能力，使得存在减少的电荷屏蔽，并且因此存在带电阴离子和结合位点之间更强的相互作用。在这个项目中，我们将开发人工疏水脂质双层，这是这样的有机感觉膜的一个例子，阴离子结合基序可以很容易地集成到这些双层。这些膜将被固定在电极表面上以获得电化学传感器。电化学电容测量将通过使用低幅值交流电施加固定电压和变化频率在电极和膜之间的界面处进行。这些电容测量将有效地探测膜能够存储电荷的能力，即磷酸盐与电极表面的膜锚定受体结合事件的频率和强度，并因此量化磷酸盐水平。该项目福尔斯属于EPSRC电化学科学，传感器和仪器，合成配位化学，合成超分子化学研究领域内的物理科学的研究主题。

Anion detection and recognition in pure water is a significant current challenge in supramolecular chemistry, to this day remains relatively unevolved as a research field. This is due to the fundamental challenges associated with sensing anions, attributed to their strong association with surrounding water molecules (high solvation energies) that needs to be broken in order to bind to a receptor. These receptors often have low solubility in water and poor selectivity for the target anion, exacerbated by weak anion affinity to the binding site.Inorganic phosphate is ubiquitous as a chemical building block in biological systems, for example being present in the majority of metabolic reactions. It is also highly environmentally relevant, whereby the rising use of fertilisers in agriculture has led to an overabundance of phosphates in waterways. This results in eutrophication, the effects of which can be seen in harmful algal blooms and hypoxic 'dead zones' of aquatic life. Common techniques of detecting phosphate levels vary from the use of traditional molecular fluorescence probes and optical analysis to NMR titration techniques. However, these lab-based methods are typically expensive, time consuming and laborious. Electrochemical sensors, in contrast, are portable, cheap and can be used in the field for continuous monitoring.The binding environment of a receptor for anions can be effectively engineered to promote high affinity, or strong binding, between the receptor and targeting anion. Sensory films exhibit measurable binding enhancement factors, where solvation effects are controlled. A practical way of controlling such effects is by using such films which afford the ability to tune the interfacial dielectric microenvironment, such that there is reduced charge screening, and hence stronger interactions between the charged anion and binding site. In this project we will develop artificial hydrophobic lipid bilayers, which are an example of such organic sensory films, whereby anion binding motifs can be readily integrated into these bilayers. These membranes will be immobilised on an electrode surface in order to obtain an electrochemical sensor. Electrochemical capacitance measurements will be taken at the interface between the electrode and the film by applying a fixed voltage and varying frequency using a low magnitude alternating current. These capacitance measurements will effectively probe the ability of the film is able to store charge, i.e. the frequency and strength of binding events of phosphate to the membrane anchored receptors at the electrode surface, and as such, quantify phosphate levels.This project falls in the EPSRC electrochemical sciences, sensors and instrumentation, synthetic coordination chemistry, synthetic supramolecular chemistry research areas within the physical sciences research theme.