Photochemical oxidation is able to effectively regenerate the fouled electrode in electrochemical pollutant monitoring, while its regeneration capacity is limited by the surface-bound hydroxyl radical speciation with low activity and mobility, which is attributed to the dissociated water adsorption on hydrophilic metal oxides. In this work, fluorine-terminated {001}-exposed TiO₂ single crystals (F–TiO₂) are rationally designed to construct an Au-based electrochemical sensor (Au/F–TiO₂) for dopamine (DA) detection in different matrices. The Au/F–TiO₂ sensor exhibits an efficient and stable detection capacity in both environmental and biological samples. A superior photochemical regeneration capacity is obtained on the Au/F–TiO₂ electrode with much reduced matrix effects under UV irradiation. Spectral observation, crystallographic analysis, pollutant degradation performance, radical inhibition, and surface enhanced Raman scattering tests reveal that both the fluorine-terminated surface chemical features and the bulk-free radical speciation are mainly responsible for the superior photochemical regeneration capacity of the Au/F–TiO₂ electrode. Even for the real biological samples, a stable electrochemical DA detection is also achieved on the Au/F–TiO₂ sensor. Our work establishes a new approach to refine electrochemical sensors for stable monitoring and provides a robust photoactive electrode substrate with high efficiency and low cost for practical applications.

中文翻译：

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用暴露于氟的{001}暴露的TiO2单晶传感器稳定地电化学测定多巴胺。

光化学氧化能够在电化学污染物监测中有效地再生污垢电极，而其再生能力却受到表面结合的羟基自由基形态的限制，该形态具有较低的活性和迁移率，这归因于亲水性金属氧化物上的离解水吸附。在这项工作中，合理设计了暴露于氟的{001}暴露的TiO ₂单晶（F–TiO ₂），以构建用于在不同基质中检测多巴胺（DA）的基于金的电化学传感器（Au / F–TiO ₂）。 。Au / F-TiO ₂传感器在环境和生物样品中均显示出有效而稳定的检测能力。Au / F-TiO具有优异的光化学再生能力_2个电极在紫外线照射下具有大大降低的基体效应。光谱观察，晶体学分析，污染物降解性能，自由基抑制和表面增强拉曼散射测试表明，氟封端的表面化学特征和本体自由基的形态都主要负责Au / F的优异光化学再生能力–TiO ₂电极。即使对于真实的生物样品，也可以在Au / F-TiO ₂传感器上实现稳定的电化学DA检测。我们的工作建立了改进电化学传感器以进行稳定监控的新方法，并为实际应用提供了高效，低成本的坚固光敏电极基材。