DEVELOPMENT OF SELF REFERENCING ELECTROCHEMICAL MICROSENSORS OXYGEN

自参考电化学微型氧气传感器的研制

• 批准号: 6120168
• 负责人: D M PORTERFIELD
• 金额: $ 9.36万
• 依托单位: MARINE BIOLOGICAL LABORATORY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120168
• 关键词: bioengineering /biomedical engineering; biomedical equipment development; biomedical resource; building /facility design /renovation; technology /technique

A major objective of this funding cycle was to explore the feasibility of using electrochemical microsensors (polarographic probes- Serp) in a self-referencing modality. We began this development in the previous cycle but this year has seen accumulating evidence for the power of this new technique. Our already existing ion-selective self-referencing (Seris) systems are limited by the range of suitable commercially available ionophores. These liquid membranes must exhibit both adequate selectivity and rapid enough response times. These constraints have limited us to calcium, chloride, hydrogen and sodium detection. To expand our repertoire of molecular detection techniques we targeted the characteristic reduction oxidation potentials of certain molecules as an alternative detection method which should benefit from the same drift reduction as the old voltage and Seris systems. We began our development by targeting oxygen a clearly important metabolic signal that prior to our work could not be measured from small single cells let alone with square micron spatial accuracy. We approached the problem of oxygen detection using the translational movement of a Whalen type microelectrodes (tip diameter = 2-3?m) through a gradient at a known frequency and between known points. Accounting for the linear calibration of the electrode, the differential electrode output is converted into a directional measurement of flux using the Fick equation. Operational characteristics of the technique were determined using artificial gradients produced outside of artificial sources of oxygen flux created using a micropipette and gases of known oxygen concentrations. The experiments showed that oxygen flux values obtained from the self-referencing oxygen microelectrode matched derived values calculated from static measurements of oxygen obtained outside of the artificial source. This reporting year has seen the further refinement of our source modeling as well as the construction of our own electrodes. In addition we have begun to routinely apply this technique to small single mammalian cells held at 37oC. Thistechnique has now been applied to various experimental systems including the study of neuronal metabolism (Smith, Dubinsky), metabolism in oocytes and embryos (Keefe, Porterfield, Sardet), pollen tubes (Robinson) and the metabolic regulation of insulin secretion in ?-cells (Corkey).

本供资周期的一个主要目标是探讨 使用电化学微传感器的可行性（极谱法 探针- Serp）中的自引用模态。 我们开始这个 上一个周期的发展，但今年已经积累了 证明了这项新技术的威力 我们现有的 离子选择性自参比（Seris）系统受到以下限制： 合适的市售离子载体的范围。 这些液体 膜必须表现出足够的选择性和足够快的 响应时间。 这些限制使我们只能摄入钙， 氯化物、氢和钠检测。 为了扩大我们的剧目， 分子检测技术，我们针对的特点， 某些分子的还原氧化电位作为替代 这种检测方法应该受益于与 旧的电压和Seris系统。 我们的开发始于 靶向氧是一个明显重要的代谢信号， 我们的工作不能从小的单个细胞来衡量，更不用说 平方微米空间精度。 我们研究了氧气的问题 使用惠伦型的平移运动的检测 微电极（尖端直径= 2-3？m）通过已知梯度 频率和已知点之间。 考虑到线性 校准电极时，差分电极输出为 转换为使用Fick的通量的方向测量 方程 该技术的操作特点是 使用在人工梯度之外产生的人工梯度确定 使用微量移液管产生的氧通量源和已知的气体 氧浓度。 实验表明，氧通量值 从自参考氧微电极获得匹配 从静态氧测量值计算得出的导出值 在人造源之外。 在本报告年度， 进一步完善我们的源模型以及建设 我们自己的电极。 此外，我们已开始例行申请 这一技术适用于保持在37 ℃的小型单个哺乳动物细胞。 该技术现已应用于各种实验系统 包括神经元代谢的研究（Smith，Dubinsky）， 卵母细胞和胚胎的代谢（Keefe，Porterfield，Sardet），花粉 管（罗宾逊）和胰岛素分泌的代谢调节， ?-细胞（Corkey）。