Malinski T, Taha Z
Department of Chemistry, Oakland University, Rochester, Michigan 48309-4401.
Nature. 1992 Aug 20;358(6388):676-8. doi: 10.1038/358676a0.
Nitric oxide is an important bioregulatory molecule, being responsible, for example, for activity of endothelium-derived relaxing factor (EDRF). Acute hypertension, diabetes, ischaemia and atherosclerosis are associated with abnormalities of EDRF. Nitric oxide is thought to be a retrograde messenger in the central nervous system. The technology is not yet available for rapid detection of NO released by a single cell in the presence of oxygen and/or nitrite, so the release, distribution and reactivity of endogenous NO in biological systems cannot be analysed. Here we describe a porphyrinic microsensor that we have developed and applied to monitoring NO release in a microsystem. We selectively measured in situ the NO released from a single cell with a response time of less than 10 ms. The microsensor consists of p-type semiconducting polymeric porphyrin and a cationic exchanger (Nafion) deposited on a thermally sharpened carbon fibre with a tip diameter of approximately 0.5 microns. The microsensor, which can be operated in either the amperometric or voltammetric mode, is characterized by a linear response up to 300 microM and a detection limit of 10 nM. Nitric oxide at the level of 10(-20) mols can be detected in a single cell.
一氧化氮是一种重要的生物调节分子，例如，它负责内皮衍生舒张因子（EDRF）的活性。急性高血压、糖尿病、缺血和动脉粥样硬化都与EDRF异常有关。一氧化氮被认为是中枢神经系统中的逆行信使。目前还没有技术能够在有氧和/或亚硝酸盐存在的情况下快速检测单个细胞释放的一氧化氮，因此无法分析生物系统中内源性一氧化氮的释放、分布和反应性。在此，我们描述了一种我们开发的卟啉微传感器，并将其应用于监测微系统中的一氧化氮释放。我们以小于10毫秒的响应时间选择性地原位测量了单个细胞释放的一氧化氮。该微传感器由p型半导体聚合物卟啉和阳离子交换剂（Nafion）组成，沉积在尖端直径约为0.5微米的热锐化碳纤维上。该微传感器可以在安培法或伏安法模式下操作，其特征在于线性响应高达300微摩尔，检测限为10纳摩尔。在单个细胞中可以检测到10^(-20)摩尔水平的一氧化氮。
