Abstract The miniature sensor has become one of the most popular tools for electroactive biomarker molecule sensing, but the challenge for preparing microelectrodes of hybrid materials still exists. In this contribution, we report a novel strategy for constructing a hybrid nitrogen-doped graphene microelectrode (NGR ME) to efficiently and reliably detect neurotransmitters. The construction procedure is a simple, green, easy-to-operate multistep assembly sequence coated on a customizable micro/nanoscale substrate. Meanwhile, polydopamine (PDA) is a biologically friendly polymer and playing multiple roles. It starts from classic adhesion ability on micro/nanoscale substrates, and its rich amino functional groups electrostatically adsorbed with graphene oxide (GO). Finally, it provided a nitrogen source for nitrogen atom doping in hybrid graphene materials. Since the self-assembled multilayers undergo a pyrolysis process, the synergistic interaction between the multilayers has endowed the microelectrodes excellent electrical conductivity and electrocatalytic performance. This work demonstrates our approach to designing microelectrodes with customizable sizes, proving that it can be used for neurotransmitter sensing with high sensitivity, excellent selectivity and low detection limit (0.69 nM for DA, 6.5 nM for 5-HT), and also can be implanted into a cannula to make a portable and micro-volume device for detecting real human serum samples, which demonstrates promising prospects in clinical diagnosis.

中文翻译：

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用于神经递质高灵敏度检测的基于混合碳材料的微电极的简单多步组装

摘要 微型传感器已成为电活性生物标志物分子传感最流行的工具之一，但制备混合材料微电极的挑战仍然存在。在这项贡献中，我们报告了一种构建混合掺氮石墨烯微电极（NGR ME）的新策略，以高效可靠地检测神经递质。构建过程是一个简单、绿色、易于操作的多步骤组装序列，涂覆在可定制的微/纳米级基板上。同时，聚多巴胺（PDA）是一种生物友好型聚合物，具有多种作用。它始于在微/纳米级基材上的经典粘附能力，其丰富的氨基官能团与氧化石墨烯 (GO) 静电吸附。最后，它为杂化石墨烯材料中的氮原子掺杂提供了氮源。由于自组装多层膜经历了热解过程，多层膜之间的协同相互作用赋予了微电极优异的导电性和电催化性能。这项工作展示了我们设计具有可定制尺寸的微电极的方法，证明它可用于神经递质传感，具有高灵敏度、出色的选择性和低检测限（DA 为 0.69 nM，5-HT 为 6.5 nM），也可以植入插入套管制成便携式微量装置，用于检测真实人血清样本，在临床诊断中显示出广阔的前景。多层之间的协同相互作用赋予微电极优异的导电性和电催化性能。这项工作展示了我们设计具有可定制尺寸的微电极的方法，证明它可用于神经递质传感，具有高灵敏度、出色的选择性和低检测限（DA 为 0.69 nM，5-HT 为 6.5 nM），也可以植入插入套管制成便携式微量装置，用于检测真实人血清样本，在临床诊断中显示出广阔的前景。多层之间的协同相互作用赋予微电极优异的导电性和电催化性能。这项工作展示了我们设计具有可定制尺寸的微电极的方法，证明它可用于神经递质传感，具有高灵敏度、出色的选择性和低检测限（DA 为 0.69 nM，5-HT 为 6.5 nM），也可以植入插入套管制成便携式微量装置，用于检测真实人血清样本，在临床诊断中显示出广阔的前景。