L-lactate measures in brain tissue with ceramic-based multisite microelectrodes
L-lactate measures in brain tissue with ceramic-based multisite microelectrodes
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DOI：
10.1016/j.bios.2004.07.003
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发表时间：
2005-03-15
影响因子：
12.6
通讯作者：
Gerhardt, GA
中科院分区：
文献类型：
--
作者：
Burmeister, JJ;Palmer, M;Gerhardt, GA
本文报道了一种新研制的用于L-乳酸在体测定的多位点阵列微电极。所得到的微电极由三个功能层组成。首先，Nation用于排斥干扰的电活性阴离子，如抗坏血酸盐。其次，固定在记录位点上的L-乳酸氧化酶用于将L-乳酸转化为过氧化氢。产生的H2 O2与L-乳酸浓度成比例，并在铂记录位点进行定量。第三，在L-乳酸氧化酶上涂覆一层聚氨酯，以将微电极的线性范围调整到与体内测量兼容的范围。该层减少扩散到酶的L-乳酸的量，同时不显著限制氧扩散。所得L-乳酸盐微电极在20 mM（R-2 = 0.997 +/- 0.001）下呈线性，在某些情况下超过20 mM，检测限为0.078 +/- 0.013 mM（n = 12）。这些电极的选择性和响应时间使它们适合于脑组织中的体内测量。可以利用自参考记录来进一步提高记录的选择性。然而，这对于大脑中的大多数应用来说是不必要的，因为多巴胺（DA）、去甲肾上腺素（NE）和其他潜在干扰阳离子的静息和刺激水平比在毫摩尔范围内的体内L-乳酸盐低两到三个数量级。对麻醉大鼠脑中L-乳酸的初步体内测量支持微电极能够测量体内快速内源性变化。(C)2004 Elsevier B. V.保留所有权利。
A newly developed multisite array microelectrode for in vivo measurements Of L-lactate is presented. The resulting microelectrode is composed of three functional layers. First, Nation is used to repel interfering electroactive anions, such as ascorbate. Second, L-lactate oxidase immobilized onto the recording sites is used to convert L-lactate to hydrogen peroxide. The H2O2 produced is proportional to L-lactate concentrations and is quantified at the platinum recording sites. Third, a layer of polyurethane is coated over the L-lactate oxidase to adjust the linear range of the microelectrode to one that is compatible with in vivo measurements. This layer reduces the amount Of L-lactate that diffuses to the enzyme while not significantly limiting oxygen diffusion. The resulting L-lactate microelectrodes were linear to 20 mM (R-2 = 0.997 +/- 0.001) and beyond in some cases with detection limits of 0.078 +/- 0.013 mM (n = 12). The selectivity and response time of these electrodes make them suitable for in vivo measurements in brain tissue. Self-referencing recordings may be utilized to further improve the selectivity of the recordings. However this is not necessary for most applications in the brain, because the resting and stimulated levels of dopamine (DA), norepinephrine (NE), and other potentially interfering cations are two to three orders of magnitude lower than that of in Vivo L-lactate, which is in the millimolar range. Preliminary in vivo measures Of L-lactate in the brain of anesthetized rats support that the microelectrodes are capable of measuring rapid endogenous changes in vivo. (C) 2004 Elsevier B.V. All rights reserved.