TEMPORAL CHARACTERIZATION OF PERFLUORINATED ION-EXCHANGE COATED MICROVOLTAMMETRIC ELECTRODES FOR INVIVO USE
TEMPORAL CHARACTERIZATION OF PERFLUORINATED ION-EXCHANGE COATED MICROVOLTAMMETRIC ELECTRODES FOR INVIVO USE
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DOI：
10.1021/ac00141a003
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发表时间：
1987-07-15
影响因子：
7.4
通讯作者：
WIGHTMAN, RM
中科院分区：
文献类型：
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作者：
KRISTENSEN, EW;KUHR, WG;WIGHTMAN, RM
全氟离子交换（PFIE）涂层，微伏安电极的矩形浓度变化的时间响应进行了评价。这些具有微米尖端尺寸的装置已被设计用作电活性神经递质（如多巴胺）的体内探针。多巴胺在具有薄于200 nm的PFIE膜的电极处的渗透足够快，使得浓度脉冲的失真不明显。Ru（bpy）32+在这些薄膜中的渗透速率随外加电位波形而变化。在恒定的施加电位下，测得的渗透速率随着重复暴露而增加。然而，以1秒的间隔重复快速扫描循环伏安法（200 V s-1），随着重复暴露，Ru（bpy）32+的渗透时间保持相对恒定。当以这种方式取样时，通过这些膜的物理扩散对于该复合物占主导地位。每个单独膜的厚度可以由渗透速率确定。多巴胺在这些薄的PFIE膜中的扩散系数被发现随着溶液中钠离子浓度的降低而降低。PFIE膜中多巴胺的伏安图类似于溶液中的伏安图，除了在膜的高负载下，其中可以超过缓冲容量。发现电极对麻醉大鼠脑中多巴胺的刺激分泌迅速响应。
The temporal response of perfluorinated ion exchange (PFIE) coated, microvoltammetric electrodes to rectangular concentration changes has been evaluated. These devices, with micrometer tip dimensions, have been designed for use as in vivo probes of electroactive neurotransmitters such as dopamine. The permeation of dopamine at electrodes with PFIE films thinner than 200 nm is sufficiently fast that distortion of the concentration pulse is not apparent. The permeation rate of Ru(bpy)32+ into these films varies with the applied potential waveform. At constant applied potential the measured permeation rate increases with repetitive exposure. However, with fast-scan cyclic voltammetry (200 V s-1) repeated at 1-s intervals the permeation time for Ru(bpy)32+ remains relatively constant with repetitive exposures. Physical diffusion through these films predominates for this complex when sampled in this manner. The thickness of each individual film can be determined from the permeation rates. The diffusion coefficient for dopamine in these thin PFIE films is found to decrease with decrease in sodium ion concentration in solution. Voltammograms of dopamine in PFIE films are similar to those in solution except at high loading of the film where the buffer capacity can be exceeded. The electrodes are found to respond rapidly to the stimulated secretion of dopamine in the brain of an anesthetized rat.