Real-Time Detection of Glutamate using Templated Polymers as Shape-Changing Target Receptors

项目摘要/摘要 对一种新的传感技术的需求很大，它可以连续监测大脑中的神经化学物质。 具有高时间分辨率的实时图像。虽然电化学检测电活性神经递质(例如 如多巴胺和5-羟色胺)已经成功地使用高频伏安法(例如快速- 扫描循环伏安法)，非电活性物种(如谷氨酸)的测量仍然是一种很大的 实现高时间分辨率实时监测的挑战。该项目的目标是实现一个 可监测著名非电活性物质谷氨酸的新型电化学传感平台 神经递质，具有生理相关的检测范围和高时间分辨率。建议数 传感方法可以作为酶传感或微渗析的替代方法，后者具有一定的局限性 在时间分辨率和稳定性方面。部分受到基于适配子的电化学传感器的激励， 所提出的传感机制利用新的合成目标受体作为目标识别单元和 信号换能器。谷氨酸受体是由单链刺激反应模板聚合物形成的 它与其模板分子，即谷氨酸特异结合。此外，在选择目标时 识别后，聚合物经历构象变化(从线形到折叠形状)。聚合物的这种变化 形态可以通过使用附着的氧化还原报告(如二茂铁)进行电化学检测 到聚合物。为了验证所提出的传感方法，所开发的传感器将与 两种成熟的方法，膜片钳和微透析技术。膜片钳系统适用于 然而，测量神经元突触裂隙的快速化学交换动力学(毫秒)， 缺乏化学特异性。微透析液相色谱质谱联用技术 提供了特殊的化学特异性，然而，时间分辨率很差(大约几分钟)。它 预计开发的传感器平台将能够弥合这两种现有方法之间的差距 并在感测性能上提供多功能性。这个项目的目标将通过追求 具体目标如下：(1)优化模板化聚合物谷氨酸受体以满足所需 性能指标；以及(2)在生理环境中验证所开发的谷氨酸传感器。这个 该项目的成功成果将是开发一种新的通用平台技术来检测 实时的神经化学物质，时间分辨率也足以研究突触通讯 至于监测脑组织细胞外区域的化学物质。

PROJECT SUMMARY / ABSTRACT There is a great demand for a new sensing technology that can monitor neurochemicals in brain continuously in real-time with high temporal resolution. While electrochemical detection of electroactive neurotransmitters (such as dopamine and serotonin) have been successful using high frequency voltammetric methods (such as fast- scan cyclic voltammetry), measurement of non-electroactive species (such as glutamate) still remain a great challenge for achieving real-time monitoring with high time resolution. The goal of this project is to implement a new electrochemical sensing platform that can monitor glutamate, a well-known non-electroactive neurotransmitter, with physiologically relevant detection range and high temporal resolution. The proposed sensing approach can serve as an alternative to enzymatic sensing or microdialysis which have some limitations with respect to time resolution and stability. Motivated in part by the aptamer-based electrochemical sensors, the proposed sensing mechanism utilizes a novel synthetic target receptor as both a target recognition unit and a signal transducer. The glutamate receptor is formed by a single-chain stimuli-responsive templated polymer that binds specifically to its template molecule, namely, glutamate. Furthermore, upon selective target recognition, the polymer undergoes conformation change (from linear to folded shape). This change in polymer morphology can be electrochemically detected through the use of a redox reporter (such as ferrocene) attached to the polymer. For validation of the proposed sensing approach, the developed sensor will be compared against two well-established methods, a patch clamp and a microdialysis technique. A patch clamp system is ideal for measuring fast dynamics (milliseconds) of chemical exchange at the synaptic cleft of the neurons, however, lacks chemical specificity. A microdialysis in conjunction with liquid chromatography and mass spectrometry provides exceptional chemical specificity, however, the temporal resolution is poor (on the order of minutes). It is expected that the developed sensor platform will be able to bridge the gap between these two existing methods and to provide versatility in sensing performances. The goals of this project will be achieved by pursuing the following specific aims: (1) optimization of the templated polymer-based glutamate receptor to meet the desired performance metrics; and (2) validation of the developed glutamate sensor in a physiological environment. The successful outcome of this project will be the development of a new general platform technology for detection of neurochemicals in real-time with a time resolution that is sufficient for studying synaptic communications as well as for monitoring chemicals in the extracellular regions in the brain tissue.