In Vivo Monitoring of H2O2 with Polydopamine and Prussian Blue-coated Microelectrode

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• 作者：Ruixin Li ; Xiaomeng Liu ; Wanling Qiu ; Meining Zhang
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：August 2, 2016
• 年：2016
• 卷：88
• 期：15
• 页码：7769-7776
• 全文大小：492K
• 年卷期：0
• ISSN：1520-6882

文摘

In vivo monitoring of hydrogen peroxide (H₂O₂) in the brain is of importance for understanding the function of both reactive oxygen species (ROS) and signal transmission. Producing a robust microelectrode for in vivo measurement of H₂O₂ is challenging due to the complex brain environment and the instability of electrocatalysts employed for the reduction of H₂O₂. Here, we develop a new kind of microelectrode for in vivo monitoring of H₂O₂, which is prepared by, first, electrodeposition of Prussian blue (PB) onto carbon nanotube (CNT) assembled carbon fiber microelectrodes (CFEs) and then overcoating of the CFEs with a thin membrane of polydopamine (PDA) through self-polymerization. Scanning electron microscopic and X-ray proton spectroscopic results confirm the formation of PDA/PB/CNT/CFEs. The PDA membrane enables PB-based electrodes to show high stability in both in vitro and in vivo studies and to stably catalyze the electrochemical reduction of H₂O₂. The microelectrode is selective for in vivo measurements of H₂O₂, interference-free from O₂ and other electroactive species coexisting in the brain. These properties, along with good linearity, high biocompatibility, and stability toward H₂O₂, substantially enable the microelectrode to track H₂O₂ changes in vivo during electrical stimulation and microinfusion of H₂O₂ and drug, which demonstrates that the microelectrode could be well suited for in vivo monitoring of dynamic changes of H₂O₂ in rat brain.