Yuan Yang, Jia Hui, Wang Jie
State Key Laboratory of Separation Membranes and Membrane Processes, Tiangong University, Tianjin 300387, China.
School of Material Science and Engineering, Tiangong University, Tianjin, 300387, China.
Anal Methods. 2022 Oct 6;14(38):3802-3813. doi: 10.1039/d2ay01016j.
Among various detection and analysis platforms, a microfluidic chip-based electrochemical sensing detection platform is a new type of detection platform. In this study, a microfluidic electrochemical detection platform for cadmium ion detection is proposed, and the performance of the detection platform is optimized in terms of both the microchannel size and electrode modifications. The detection mixing processes of the detector with different microchannel sizes, including the concentration distribution in the channel, pressure decay variation and electrolyte current density variation in the detector, were investigated by finite element model calculations. The analysis shows that the size of the microchannel in the detector affects the fluid and thus further affects the chemical reaction. If the size of the electrode does not match the size of the microchannel, insufficient sample volume will lead to inaccurate measurements, reduced sensitivity and increased detection limits. It was found that the sensitivity of the electrochemical sensor was highest when the size of the microchannel in the chip was 400 μm. After optimization, the optimal detection limit for cadmium ions was 0.03 μg L (S/N = 3). The proposed sensing platform is simple in design and stable in structure, and is suitable for field screening and rapid response to heavy metal contamination events.
在各种检测和分析平台中，基于微流控芯片的电化学传感检测平台是一种新型检测平台。本研究提出了一种用于镉离子检测的微流控电化学检测平台，并从微通道尺寸和电极修饰两方面对检测平台的性能进行了优化。通过有限元模型计算研究了不同微通道尺寸的检测器的检测混合过程，包括通道内的浓度分布、压力衰减变化以及检测器内的电解质电流密度变化。分析表明，检测器中微通道的尺寸会影响流体，进而影响化学反应。如果电极尺寸与微通道尺寸不匹配，样品体积不足将导致测量不准确、灵敏度降低和检测限增加。研究发现，当芯片中微通道尺寸为400μm时，电化学传感器的灵敏度最高。优化后，镉离子的最佳检测限为0.03μg/L（信噪比=3）。所提出的传感平台设计简单、结构稳定，适用于现场筛查和对重金属污染事件的快速响应。
