A Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, P. R. China.
The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, Hunan Provincial Key Laboratory of Neurorestoratology, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410006, P.R. China.
ACS Sens. 2022 Jan 28;7(1):235-244. doi: 10.1021/acssensors.1c02051. Epub 2021 Dec 22.
monitoring of cerebral pH is of great significance because its disturbance is related to some pathological processes such as neurodegenerative diseases, for example, Parkinson's disease (PD). In this study, we developed an electrochemical microsensor based on poly(melamine) (P) films for ratiometric monitoring of pH in subacute PD mouse brains. In this microsensor, P films were prepared from a simple electropolymerization approach in a melamine-containing solution, serving as the selective pH recognition membrane undergoing a 2H/2e process. Meanwhile, electrochemically oxidized graphene oxide (EOGO) produced a built-in correction signal which helped avoid the environmental interference of the complicated brain systems. The potential difference between the peaks generated from EOGO and P gradually decreased with the aqueous pH increasing from 4.0 to 9.0, constituting the detection foundation of the ratiometric electrochemical microsensor (REM). The studies demonstrated that this proposed method exhibited a high sensitivity (a Nernstian response of -61.35 mV/pH) and remarkable selectivity against amino acids, anions, cations, and biochemical and reactive oxygen species coexisting in the brain. Coupled with its excellent stability and reproducibility and good antibiofouling based on short-term detection, the developed REM could serve as a disposable sensor for the determination of cerebral pH . Its following successful application in the real-time measurement of pH in the striatum, hippocampus, and cortex of rat brains in the events of global cerebral ischemia/reperfusion verified the reliability of this method. Finally, we adopted this robust REM to systematically analyze and compare the average pH in different regions of normal and subacute PD mouse brains.
监测脑 pH 值具有重要意义，因为其紊乱与一些病理过程有关，例如神经退行性疾病，例如帕金森病 (PD)。在这项研究中，我们开发了一种基于聚（三聚氰胺）（P）薄膜的电化学微传感器，用于亚急性 PD 小鼠大脑中 pH 值的比色监测。在该微传感器中，通过在含有三聚氰胺的溶液中进行简单的电聚合方法制备 P 薄膜，用作经历 2H/2e 过程的选择性 pH 识别膜。同时，电化学氧化的氧化石墨烯（EOGO）产生了内置的校正信号，有助于避免复杂脑系统的环境干扰。来自 EOGO 和 P 的峰之间的电位差随着水相 pH 值从 4.0 增加到 9.0 逐渐减小，构成了比率电化学微传感器 (REM) 的检测基础。研究表明，该方法表现出高灵敏度（Nernst 响应为-61.35 mV/pH）和对共存于脑中的氨基酸、阴离子、阳离子以及生化和活性氧物质的显著选择性。结合其出色的稳定性和重现性以及基于短期检测的良好抗生物污染性，所开发的 REM 可用作测定脑 pH 值的一次性传感器。它在全脑缺血/再灌注事件中成功应用于大鼠大脑纹状体、海马体和皮质中 pH 值的实时测量，验证了该方法的可靠性。最后，我们采用这种稳健的 REM 来系统地分析和比较正常和亚急性 PD 小鼠大脑不同区域的平均 pH 值。
