Abstract：
Platinum-based neural electrodes, frequently alloyed with Ir or W, are routinely used to treat neurological disorders. However, their performance is impaired by an increase in impedance that compromises long-term implant functionality. Though there are multiple coating techniques available to address this issue, electrode, and base material often exhibit a compositional mismatch, which impairs mechanical stability and may lead to toxicological side effects. In this work, we coated Pt wire electrodes with ligand-free electrostatically stabilized colloidal Pt90Ir10, Pt90W10, and Pt50W50 alloy nanoparticles (NPs) matching electrode compositions using electrophoretic deposition (EPD) with direct-current (DC) and pulsed-DC fields in aqueous medium. The generated alloy NPs exhibit a solid solution structure as evidenced by HR-TEM-EDX and XRD, though additional WOx phases were identified in the Pt50W50 samples. Consequently, coating efficiency was also impaired in the presence of high W mass fractions in the alloy NPs. Characterization of the NP coatings by cyclic voltammetry and impedance spectroscopy yielded a significant reduction of the impedance in the Pt90Ir10 sample in comparison to the control coated with Pt NPs. The electrochemical surface area (ECSA) of the PtW alloy coatings, on the other hand, was significantly reduced.
摘要：
经常与Ir或W合金化的铂基神经电极通常用于治疗神经系统疾病。然而,电极和组织之间的电接触受损，损害了植入物的长期稳定性，从而阻碍了它们的性能。虽然有多种涂层技术可用来解决这个问题，电极,和基础材料通常表现出成分不匹配，这会损害机械稳定性并可能导致毒理学副作用。在这项工作中，我们使用无配体静电稳定的胶体Pt90Ir10，Pt90W10和Pt50W50合金纳米颗粒（NPs）匹配电极组合物，使用电泳沉积（EPD）与直流（DC）和脉冲DC场在水性介质中涂覆Pt线电极。生成的合金NP表现出固溶体结构，如HR-TEM-EDX和XRD所示，尽管在Pt50W50样品中发现了额外的WOx阶段。因此,在合金NP中存在高W质量分数的情况下，涂层效率也受到损害。与Pt对照相比,通过循环伏安法和阻抗谱表征NP涂层产生Pt90Ir10样品中的阻抗的显著降低。PtW合金涂层的电化学表面积（ECSA），另一方面,显着减少。
