DEVELOPMENT OF SELF REFERENCING ELECTROCHEMICAL MICROSENSORS ASCORBIC ACID

氧和一氧化氮同时测量的使用经验 自引用探测，尤其是构建我们的 自己的碳基微型传感器为分子开辟了新的视野 通量检测。对抗坏血酸的检测进行了探讨。 哈罗德·贝尔曼的请求(B00。关于Obs的。还有妇科。耶鲁大学医学院 学校)。抗坏血酸有一种奇怪的性质，表现出 明显的胞外通量模式，伴随着缓慢的振荡 延长的时间段。这在哺乳动物身上尤为明显。 需要过滤AA电化学信号的CNS 儿茶酚胺检测。我们在这个子项目中的意图是 探索我们制造自我参照系统的能力，该系统能够 测量单细胞通量，从而有助于我们理解 潜在的AA运输生理学。这些探测器是建立在 用于施工的碱性碳纤维电极 一氧化氮探针，并进行电化学修饰，以改善 对抗坏血酸敏感。这项准备工作涉及 碳纤维(1.5V，3s；70 Hz，3V)的电化学处理 带有1.5V偏移量的三角波持续10秒；然后在0V保持 30分钟)。这导致了工作电势的降低 需要将AA从0.9V氧化到0.05V。电极是 在已知AA浓度的溶液中进行校准(线性 校准)。当这些微探针在 已经使用人工梯度验证了自参考模式， 我们还没有将它们应用于生物系统。续 自参照式电化学微传感器的研制 发生的方式有三种。其中包括开发新的 传感器，循环伏安法和计时电流法的应用， 但最快的方法是适应现有的 用于单电池的电化学探头。后者的一个例子 方法是新的自参考抗坏血酸探测器，其 发展迅速，而且比从氧气到一氧化氮更简单。我们 预计会有一份超过生物医学研究人员的“菜单” 在设计他们的实验时，他们可以从中进行选择。

Experience with both oxygen and nitric oxide measurement using self-referencing probes, and, in particular, the ability to build our own carbon based microsensors has opened up new horizons for molecular flux detection. The detection of ascorbic acid was explored on the request of Harold Behrman (B00. of Obs. and Gyn. Yale Medical School). Ascorbic acid has the curious quality of exhibiting pronounced extracellular flux patterns, with slow oscillations over extended time periods. This is particularly evident in the mammalian CNS where AA electrochemical signals need to be filtered out for catecholamine detection. Our intention in this sub-project was to explore our ability to produce a self-referencing system able to measure single cell flux and thus contribute to our understanding of the underlying AA transport physiology. These probes are built upon the basic carbon fiber electrode used for the construction of the nitric oxide probes and are modified electrochemically to improve sensitivity for ascorbic acid. This preparation involved the electrochemical treatment of a carbon fiber (1.5V for 3 sec; 70 Hz 3V triangle wave with 1.5V offset for 10 sec; followed by a hold at 0V for 30 minutes). This results in a decrease in the working potential required to oxidize AA from 0.9V to 0.05V. The electrodes are calibrated in solutions of known AA concentrations (linear calibration). While the operation of these microprobes in the self-referencing mode has been verified using an artificial gradient, we have not yet applied them to a biological system. Continued development of the self-referencing electrochemical microsensors can occur through three approaches. These include the development of new sensors, the application of cyclic voltammetry and chronoamperometry, but the most rapid approach is the adaptation of existing electrochemical probes for single cell use. An example of the later approach is the new self-referencing ascorbic acid probe whose development was rapid and simpler than moving from oxygen to NO. We anticipate being in a position to over biomedical researchers a "menu" of probes from which they can choose in designing their experiments.