A microfluidic electrochemical flow cell capable of rapid on-chip dilution for fast-scan cyclic voltammetry electrode calibration
A microfluidic electrochemical flow cell capable of rapid on-chip dilution for fast-scan cyclic voltammetry electrode calibration
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DOI：
10.1007/s00216-020-02493-z
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发表时间：
2020-02-17
影响因子：
4.3
通讯作者：
Ross, Ashley E.
中科院分区：
文献类型：
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作者：
Delong, Lauren M.;Li, Yuxin;Ross, Ashley E.
在这里，我们开发了一种用于快速扫描循环伏安法的微流体电化学流动电池，它能够快速片上稀释，从而实现高效和经济的电极校准。碳纤维微电极上的快速扫描循环伏安法（FSCV）是一种可靠的电分析技术，用于测量神经递质浓度随时间的亚秒变化。FSCV的传统电极校准方法需要几毫升的标准液。此外，生成校准曲线可能很耗时，因为必须为每种浓度准备单独的溶液。微流控电化学流动电池在过去得到了发展；然而，它们通常需要将电极结合到设备中，这使得它难以在生物组织中进行测试。同样，目前的微流控电化学流动电池也无法实现片上快速稀释，从而消除制作多种溶液的要求。我们设计了一个t通道设备，微通道尺寸为100 μ m x 50 μ m，可以将标准样品输送到直径为2mm的开放式电极取样井。设计了一个与井垂直的相同尺寸的废物通道，以冲洗和清除标准。t型微通道的尺寸和流速的选择是为了便于在到达电极之前在输送通道中完全混合。混合程度使用COMSOL计算建模，并在设备中使用有色染料和电化学检测进行定量评估。用FSCV对多巴胺进行片上电极校准与传统的校准方法没有显著差异，证明了其对FSCV校准的有效性。总体而言，该装置提高了电极校准的效率和便利性。
Here, we developed a microfluidic electrochemical flow cell for fast-scan cyclic voltammetry which is capable of rapid on-chip dilution for efficient and cost-effective electrode calibration. Fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes is a robust electroanalytical technique used to measure subsecond changes in neurotransmitter concentration over time. Traditional methods of electrode calibration for FSCV require several milliliters of a standard. Additionally, generating calibration curves can be time-consuming because separate solutions must be prepared for each concentration. Microfluidic electrochemical flow cells have been developed in the past; however, they often require incorporating the electrode in the device, making it difficult to remove for testing in biological tissues. Likewise, current microfluidic electrochemical flow cells are not capable of rapid on-chip dilution to eliminate the requirement of making multiple solutions. We designed a T-channel device, with microchannel dimensions of 100 mu m x 50 mu m, that delivered a standard to a 2-mm-diameter open electrode sampling well. A waste channel with the same dimensions was designed perpendicular to the well to flush and remove the standard. The dimensions of the T-microchannels and flow rates were chosen to facilitate complete mixing in the delivery channel prior to reaching the electrode. The degree of mixing was computationally modeled using COMSOL and was quantitatively assessed in the device using both colored dyes and electrochemical detection. On-chip electrode calibration for dopamine with FSCV was not significantly different than the traditional calibration method demonstrating its utility for FSCV calibration. Overall, this device improves the efficiency and ease of electrode calibration.