Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrene sulfonate) (PSS) is the most commonly used conducting polymer in organic bioelectronics. However, electrochemical capacitances exceeding the current state-of-the-art are required for enhanced transduction and stimulation of biological signals. The long-term stability of conducting polymer films during device operation and storage in aqueous environments remains a challenge for routine applications. In this work, we electrochemically synthesize a PEDOT composite comprising the water dispersible two-dimensional conducting material Ti₃C₂ MXene. We find that incorporating MXene as a co-dopant along with PSS leads to PEDOT:PSS:MXene films with remarkably high volumetric capacitance (607.0 ± 85.3 F cm⁻³) and stability (capacity retention = 78.44% ± 1.75% over 500 cycles), outperforming single dopant-comprising PEDOT films, i.e., PEDOT:PSS and PEDOT:MXene electropolymerized under the same conditions on identical surfaces. The stability of microfabricated PEDOT:PSS:MXene electrodes is evaluated under different conditions, i.e., when the films are exposed to sonication (∼100% retention over 6 min), upon immersion in cell culture media for 14 days (∆|Z| = 2.13%), as well as after continuous electrical stimulation. Furthermore, we demonstrate the use of a PEDOT:PSS:MXene electrode as an electrochemical sensor for sensitive detection of dopamine (DA). The sensor exhibited an enhanced electrocatalytic activity toward DA in a linear range from 1 µM to 100 μM validated in mixtures containing common interferents such as ascorbic acid and uric acid. PEDOT:PSS:MXene composite is easily formed on conductive substrates with various geometries and can serve as a high performance conducting interface for chronic biochemical sensing or stimulation applications.

中文翻译：

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MXene改善了电聚合PEDOT膜的稳定性和电化学性能

掺杂有聚苯乙烯磺酸盐（PSS）的聚（3,4-乙撑二氧噻吩）（PEDOT）是有机生物电子学中最常用的导电聚合物。然而，增强生物信号的转导和刺激需要超过当前技术水平的电化学电容。对于常规应用而言，在设备操作和在水性环境中存储期间，导电聚合物薄膜的长期稳定性仍然是一个挑战。在这项工作中，我们电化学合成了一种PEDOT复合材料，该复合材料包含水分散性二维导电材料Ti ₃ C ₂ MXene。我们发现，将MXene与PSS一起作为共掺杂剂掺入会导致PEDOT：PSS：MXene薄膜具有非常高的体积电容（607.0±85.3 F cm ^-3）和稳定性（在500个循环中容量保持率= 78.44％±1.75％）方面，胜过单个含掺杂剂的PEDOT膜，即在相同条件下在相同表面上电聚合的PEDOT：PSS和PEDOT：MXene。在不同条件下评估微细加工的PEDOT：PSS：MXene电极的稳定性，即当将膜暴露于超声处理（在6分钟内约100％保留）时，将其浸入细胞培养基中14天（Δ| Z | = 2.13％），以及持续电刺激后。此外，我们演示了使用PEDOT：PSS：MXene电极作为灵敏检测多巴胺（DA）的电化学传感器。该传感器在1 µ M至100 µ的线性范围内表现出对DA的增强电催化活性M在含有常见干扰物（例如抗坏血酸和尿酸）的混合物中验证。PEDOT：PSS：MXene复合材料可以轻松地在具有各种几何形状的导电基材上形成，并且可以作为高性能导电界面，用于慢性生化感测或刺激应用。