Microfluidic Chip-Based Online Electrochemical Detecting System for Continuous and Simultaneous Monitoring of Ascorbate and Mg2+ in Rat Brain
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- 作者：Xia Gao ; Ping Yu ; Yuexiang Wang ; Takeo Ohsaka ; Jianshan Ye ; Lanqun Mao
- 刊名：Analytical Chemistry
- 出版年：2013
- 出版时间：August 6, 2013
- 年：2013
- 卷：85
- 期：15
- 页码：7599-7605
- 全文大小：380K
- 年卷期：v.85,no.15(August 6, 2013)
- ISSN：1520-6882
文摘
This study demonstrates a microfluidic chip-based online electrochemical detecting system for in vivo continuous and simultaneous monitoring of ascorbate and Mg2+ in rat brain. In this system, a microfluidic chip is used as the detector for both species. To fabricate the detector, a single-channel microfluidic chip is developed into an electrochemical flow cell by incorporating the chip with an indium鈥搕in oxide (ITO) electrode as working electrode, an Ag/AgCl wire as reference electrode, and a stainless steel tube as counter electrode. Selective detection of ascorbate and Mg2+ is achieved by drop-coating single-walled carbon nanotubes (SWNTs) and polymerizing toluidine blue O (polyTBO) film onto the ITO electrode, respectively. Moreover, the alignment of SWNT-modified and polyTBO-modified electrodes and the solution introduction pattern are carefully designed to avoid any cross talk between two electrodes. With the microfluidic chip-based electrochemical flow cell as the detector, an online electrochemical detecting system is successfully established by directly integrating the microfluidic chip-based electrochemical flow cell with in vivo microdialysis. The microfluidic system exhibits sensing properties with a linear relationship from 5 to 100 渭M for ascorbate and from 100 to 2000 渭M for Mg2+. Moreover, this system demonstrates a high selectivity and stability and good reproducibility for simultaneous measurements of ascorbate and Mg2+ in a continuous-flow system. These excellent properties substantially render this system great potential for continuous and simultaneous online monitoring of ascorbate and Mg2+ in rat brain.