Microfabricated microelectrode sensor for measuring background and slowly changing dopamine concentrations
Microfabricated microelectrode sensor for measuring background and slowly changing dopamine concentrations
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DOI：
10.1016/j.jelechem.2013.01.022
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发表时间：
2013-03-15
影响因子：
4.5
通讯作者：
McCarty, Gregory S.
中科院分区：
文献类型：
--
作者：
Dengler, Adam K.;McCarty, Gregory S.
快速扫描循环伏安法（FSCV）具有时间分辨率高、灵敏度高、化学选择性好等优点，是生物体内神经递质电化学检测的主要方法。FSCV是一种差分技术，记录电活性神经递质（如多巴胺（DA））浓度的阶段性（秒到秒）变化。为了分离由于分析物浓度波动引起的电流，换句话说，为了进行这些相位测量，需要减去大的背景电流。减去该背景及其挥发性使得FSCV无法确定背景或缓慢变化的电活性分析物浓度。然而，仍然需要容易地确定组织中电活性分析物的背景和缓慢变化的浓度。例如，DA的背景浓度在整个大脑中变化，并且可以影响多巴胺能系统的动力学。因此，本报告提出了一种微型电化学传感器，用于测量背景和缓慢变化的DA浓度在体外的选择性和灵敏度的FSCV。该传感器由两个微加工的微电极组成，它们间隔8 μ m。改变外电极的施加电势操纵电活性物质的局部浓度，包括在内电极处的浓度。使用FSCV在内电极处测量这些变化。校正后的信号可以测定背景和缓慢变化的DA浓度，具有FSCV的选择性和灵敏度。在这项研究中，DA的背景测定在体外使用该传感器。DA信号被示出为在外部电极处的吸附/解吸的结果。抗坏血酸对DA信号的干扰被证明是最小的这种方法。(C)2013爱思唯尔有限公司版权所有。
The electrochemical detection of neurotransmitters in vivo has centered on fast scan cyclic voltammetry (FSCV) due to its temporal resolution, sensitivity and chemical selectivity. FSCV is a differential technique that records phasic (second-to-second) changes in the concentration of electroactive neurotransmitters such as dopamine (DA). To isolate the currents due to fluctuations in analyte concentration, in other words to make these phasic measurements, requires the subtraction of a large background current. The subtraction of this background and its volatility renders FSCV unable to determine background or slowly varying concentrations of electroactive analytes. However, there is still a need to readily determine the background and slowly changing concentrations of electroactive analytes in tissue. For example, the background concentrations of DA vary throughout the brain and can affect the dynamics of dopaminergic systems. So, this report presents a microfabricated electrochemical sensor for measuring background and slowly changing concentrations of DA in vitro with the selectivity and sensitivity of FSCV. The sensor is comprised of two microfabricated microelectrodes which are spaced 8 mu m apart. Varying the applied potential of the outer electrode manipulates the local concentration of electroactive species including concentration at the inner electrode. These changes are measured at the inner electrode using FSCV. The resulting signal with calibration can determine the background and slowly changing concentration of DA with the selectivity and sensitivity of FSCV. In this study the background of DA is determined in vitro using this sensor. The DA signal is shown to be the result of adsorption/desorption at the outer electrode. Interference from ascorbate on the DA signal is shown to be minimal for this approach. (C) 2013 Elsevier B.V. All rights reserved.