Purine Functional Group Type and Placement Modulate the Interaction with Carbon-Fiber Microelectrodes
Purine Functional Group Type and Placement Modulate the Interaction with Carbon-Fiber Microelectrodes
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DOI：
10.1021/acssensors.8b01504
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发表时间：
2019-02-01
期刊：
影响因子：
8.9
通讯作者：
Ross, Ashley E.
中科院分区：
文献类型：
--
作者：
Lim, Gary N.;Ross, Ashley E.
在过去的十年中，在碳纤维微电极（CFME）上用快速扫描循环伏安法（FSCV）检测大脑中的嘌呤变得越来越受欢迎;尽管兴趣越来越大，但对嘌呤如何在快速扫描速率下与CFME相互作用的深入分析尚未研究。在这里，我们展示了嘌呤环中的官能团类型和位置如何调节灵敏度，电子转移动力学和碳纤维表面上的吸附。在CFME与FSCV的儿茶酚胺相互作用的类似调查已经通知了新的基于儿茶酚胺的传感器的开发，并且需要基于嘌呤的传感器。我们测试了在环上不同位置取代氨基、羰基或两个官能团的嘌呤碱基和未取代的嘌呤。未取代的嘌呤显示与电极表面的相互作用非常小或没有，表明官能团对于CFME处的相互作用是重要的。嘌呤核苷和核苷酸，如腺苷、鸟苷和三磷酸腺苷，由于其在大脑中丰富的细胞外信号传导模式，最常使用FSCV探测。因此，还评估了核糖和三磷酸基团影响嘌呤-CFME相互作用的程度。氨基官能团促进嘌呤类似物与CFME的相互作用比羰基，允许强吸附和高表面覆盖。核糖和三磷酸基团降低了氧化电流，减缓了电极上的相互作用，这可能是由于空间效应和静电排斥。这项工作提供了深入了解的因素，影响嘌呤CFME相互作用和条件时，考虑开发嘌呤靶向传感器FSCV。
Purine detection in the brain with fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes (CFME) has become increasingly popular over the past decade; despite the growing interest, an in-depth analysis of how purines interact with the CFME at fast-scan rates has not been investigated. Here, we show how the functional group type and placement in the purine ring modulate sensitivity, electron transfer kinetics, and adsorption on the carbon-fiber surface. Similar investigations of catecholamine interaction at CFME with FSCV have informed the development of novel catecholamine-based sensors and is needed for purine-based sensors. We tested purine bases with either amino, carbonyl, or both functional groups substituted at different positions on the ring and an unsubstituted purine. Unsubstituted purine showed very little to no interaction with the electrode surface, indicating that functional groups are important for interaction at the CFME. Purine nucleosides and nucleotides, like adenosine, guanosine, and adenosine triphosphate, are most often probed using FSCV due to their rich extracellular signaling modalities in the brain. Because of this, the extent to which the ribose and triphosphate groups affect the purine-CFME interaction was also evaluated. Amino functional groups facilitated the interaction of purine analogues with CFME more than carbonyl groups, permitting strong adsorption and high surface coverage. Ribose and triphosphate groups decreased the oxidative current and slowed the interaction at the electrode which is likely due to steric effects and electrostatic repulsion. This work provides insight into the factors that affect purine-CFME interaction and conditions to consider when developing purine-targeted sensors for FSCV.