Highly selective and sensitive in vivo neurotransmitter dynamic monitoring of the central nervous system has long been a challenging endeavor. Here, an implantable and biocompatible microsensor with excellent performances was reported by electrodepositing poly(3,4-ethylenedioxythiophene)-electrochemically reduced graphene oxide (PEDOT-ERGO) nanocomposites and poly(tannic acid) (pTA) sequentially on the carbon fiber electrode (CFE) surface, and its feasibility in in vivo electrochemical sensing applications were demonstrated. Due to the synergistic electrocatalytic effect of PEDOT-ERGO nanocomposites with the negative-charged pTA on dopamine (DA) redox reaction, the microsensor exhibits high detection sensitivities of 1.1 and 0.37 nA μM^–1 in the detection ranges of 0.02–0.5 and 0.5–20 μM with a low limit of detection of 9.2 nM. Also, the microsensor shows excellent selectivity, good sensing stability, repeatability, and reproducibility. In addition, the highly hydrophilic and negative-charged pTA inhibits the nonspecific adsorption of hydrophobic proteins, which endows the microsensor with good antifouling ability. Moreover, DA dynamics in rat brain were successfully monitored in real time, and the selective sensing ability of the microsensor in vivo was also demonstrated. The present study provides a new method for selective dynamics monitoring of DA in the brain, which would help to better understand the pathological and physiological functions of DA.

中文翻译：

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高灵敏度和生物相容性微型传感器用于大鼠大脑中多巴胺的选择性动态监测


长期以来，中枢神经系统的高选择性和灵敏度体内神经递质动态监测一直是一项具有挑战性的工作。本文通过在碳纤维电极 （CFE） 表面依次电沉积聚（3,4-乙烯二氧噻吩）-电化学还原氧化石墨烯 （PEDOT-ERGO） 纳米复合材料和聚单宁酸 （pTA），报道了一种具有优异性能的植入式和生物相容性微型传感器，并证明了其在体内电化学传感应用中的可行性。由于 PEDOT-ERGO 纳米复合材料与带负电荷的 pTA 对多巴胺 （DA） 氧化还原反应的协同电催化作用，该微传感器在 0.02-0.5 和 0.5-20 μM 的检测范围内表现出 1.1 和 0.37 nA μM^–1 的高检测灵敏度，检测限为 9.2 nM。此外，该微型传感器还表现出优异的选择性、良好的传感稳定性、可重复性和再现性。此外，高度亲水性和带负电荷的 pTA 抑制了疏水蛋白的非特异性吸附，这使微型传感器具有良好的防污能力。此外，成功实时监测大鼠大脑中的 DA 动力学，还证明了微传感器在体内的选择性传感能力。本研究为大脑 DA 的选择性动态监测提供了一种新方法，有助于更好地了解 DA 的病理和生理功能。