SIMULTANEOUS, SELECTIVE DETECTION OF CATECHOLAMINERGIC AND INDOLAMINERGIC SIGNALS USING CYCLIC VOLTAMMETRY WITH TREATED MICRO-SENSOR
SIMULTANEOUS, SELECTIVE DETECTION OF CATECHOLAMINERGIC AND INDOLAMINERGIC SIGNALS USING CYCLIC VOLTAMMETRY WITH TREATED MICRO-SENSOR
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DOI：
10.1016/0165-0270(94)00043-g
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发表时间：
1995-09-01
影响因子：
3
通讯作者：
TRIST, DG
中科院分区：
文献类型：
--
作者：
CRESPI, F;ENGLAND, TG;TRIST, DG
儿茶酚和吲哚在体内和体外的选择性和同时伏安分析迄今为止仅通过“慢”扫描方法（扫描速度在几十秒内）如差分脉冲（DPV）和差分正常脉冲伏安法结合电和/或化学处理的碳纤维微电极（mCFE）是可行的。更快的电化学技术，如计时电流法和循环伏安法（CV），可以更快（秒或几分之一秒）和更频繁地测量这些化学品。然而，这些方法在具有相似氧化电位的不同电活性化合物的存在下显示出差的灵敏度和选择性。为了分析快速伏安法的灵敏度和选择性的缺乏是由于测量的快速性还是由于使用未处理的传感器造成的，CV（扫描速度：1000 mV/s）和DPV（扫描速度：10 mV/s）的方法已经应用于未处理或电处理的mCFE以分析DA和5-HT的体外氧化电位和电流值。当与未处理的mCFE相关联时，两种方法都不能分离和选择性地检测在惰性载体中溶解在一起的两种化合物;记录的伏安图导致单一的宽氧化信号。相比之下，当使用电处理的mCFE进行这些技术时，分别在约+ 65 mV和+ 240 mV（DPV）以及+ 120 mV和+ 300 mV（CV）下同时监测DA（峰A）和5-HT（峰B）的氧化信号。此外，在麻醉大鼠上用处理的mCFE进行CV，同时监测大约+100 mV和+300 mV的两个纹状体信号。在对照记录期间，这些峰的氧化值（E（m））和电流水平（nA）保持稳定。通过外周注射氟奋乃静（DA拮抗剂）或5-羟色氨酸（5-羟色胺的前体），电流水平选择性增加。因此，这两个峰的化学性质可分别被认为是儿茶酚胺能和吲哚胺能。因此，本报告提供了第一个证据，同时在体外分析DA和5-HT使用快速扫描方法，如CV的可行性。此外，用CV-mCFE获得的DA和5-HT的电流水平（nA）的值与用DPV-mCFE监测的值相当，支持传感器的处理是增加这些伏安法技术的选择性和灵敏度的关键点的观点。还证明了使用CV与电处理的mCFE用于儿茶酚和吲哚活性的快速体内分析的可行性。
Selective and simultaneous voltammetric analysis of catechols and indoles in vivo and in vitro has until now been feasible only by means of 'slow' scanning methods (scan speed in tens of seconds) such as differential pulse (DPV) and differential normal pulse voltammetry in conjunction with electrically and/or chemically treated carbon-fiber micro-electrodes (mCFE). Faster electrochemical techniques, such as chronoamperometry and cyclic voltammetry (CV), allow more rapid (seconds or fractions of a second) and frequent measurements of these chemicals. However, these methods show poor sensitivity and selectivity in the presence of different electroactive compounds with similar oxidation potentials. In order to analyze whether the lack of sensitivity and selectivity of the fast voltammetric methods results from the rapidity of the measurement or from the use of untreated sensors, the methods of CV (scan speed: 1000 mV/s) and DPV (scan speed: 10 mV/s) have been applied with either untreated or electrically treated mCFE to analyze the in vitro oxidation potential and current values of DA and 5-HT. When associated with untreated mCFE, neither method was able to separate and selectively detect the two compounds dissolved together in an inert vehicle; the voltammogram recorded resulted in a single broad oxidation signal. In contrast, when these techniques were performed with electrically treated mCFE, oxidation signals for DA (peak A) and 5-HT (peak B) were monitored simultaneously at approximately + 65 mV and + 240 mV, with DPV respectively, and at + 120 mV and + 300 mV with CV, respectively. Additionally, CV with treated mCFE on anesthetized rats, simultaneously monitored two striatal signals at approximately + 100 mV and + 300 mV. The oxidation values (E(m)) and current levels (nA) of these peaks remained stable during control recordings. The current levels were selectively increased by peripheral injection of fluphenazine (DA antagonist) or of 5-hydroxytryptophan (precursor of serotonin). The chemical nature of these two peaks may therefore be considered catecholaminergic and indolaminergic, respectively. Hence, this report provides the first evidence for the feasibility of concomitant in vitro analysis of DA and 5-HT using a rapid scanning method such as CV. In addition, the values of current level (nA) obtained with CV-mCFE for DA and 5-HT are comparable to those monitored with DPV-mCFE, supporting the view that treatment of the sensor is a key point for increasing the selectivity and the sensitivity of these voltammetric techniques. The feasibility of using CV with electrically treated mCFE for fast in vivo analysis of catechol and indole activities is also demonstrated.