This letter reports on electrochemical and optical characteristics of flexible, transparent microelectrodes, which consist of thin poly-(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) spun onto indium-tin-oxide (ITO) electrodes for potential applications in biomedical optoelectronic devices. Although PEDOT:PSS/ITO combined films have been extensively investigated for applications in optical devices, such as solar cells and LEDs, PEDOT:PSS/ITO films for use in electrophysiological recording have not been well characterized yet. In this letter, PEDOT:PSS-coated ITO microelectrodes with various diameters of 10, 37, 50, and 80 μm were microfabricated and characterized, and their properties were compared with plain ITO microelectrodes. Experimental results demonstrate that PEDOT:PSS-coated ITO electrodes exhibit decreased electrochemical impedance, well-performed stability in saline, and increased charge storage capacity while preserving excellent optical transparency and mechanical flexibility. Equivalent circuit models were fitted to the experimental results to analytically extract interface capacitance, charge transfer resistance, and solution resistance at the electrode–electrolyte interface.

中文翻译：

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透明 PEDOT:PSS 涂层氧化铟锡 (ITO) 微电极的特性

这封信报告了柔性透明微电极的电化学和光学特性，该微电极由薄的聚（3, 4-亚乙基二氧噻吩）/聚（苯乙烯磺酸盐）（PEDOT：PSS）组成，旋涂在氧化铟锡 (ITO) 电极上以获得电位在生物医学光电器件中的应用。尽管 PEDOT:PSS/ITO 复合薄膜已被广泛研究用于光学器件，如太阳能电池和 LED，但用于电生理记录的 PEDOT:PSS/ITO 薄膜尚未得到很好的表征。在这封信中，对 PEDOT:PSS 涂层的 ITO 微电极具有 10、37、50 和 80 μm 的各种直径进行了微制造和表征，并将它们的性能与普通 ITO 微电极进行了比较。实验结果表明，PEDOT：PSS 涂层的 ITO 电极表现出较低的电化学阻抗、在盐水中表现良好的稳定性和增加的电荷存储容量，同时保持优异的光学透明度和机械柔韧性。等效电路模型拟合实验结果，以分析提取电极-电解质界面处的界面电容、电荷转移电阻和溶液电阻。