In this work, all three electrodes in an electrochemical cell were fabricated based on carbon nanotube (CNT) thread. CNT thread partially insulated with a thin polystyrene coating to define the microelectrode area was used as the working electrode; bare CNT thread was used as the auxiliary electrode; and a micro quasi-reference electrode was fabricated by electroplating CNT thread with Ag and then anodizing it in chloride solution to form a layer of AgCl. The Ag|AgCl coated CNT thread electrode provided a stable potential comparable to the conventional liquid-junction type Ag|AgCl reference electrode. The CNT thread auxiliary electrode provided a stable current, which is comparable to a Pt wire auxiliary electrode. This all-CNT thread three electrode cell has been evaluated as a microsensor for the simultaneous determination of trace levels of heavy metal ions by anodic stripping voltammetry (ASV). Hg²⁺, Cu²⁺, and Pb²⁺ were used as a representative system for this study. The calculated detection limits (based on the 3σ method) with a 120 s deposition time are 1.05, 0.53, and 0.57 nM for Hg²⁺, Cu²⁺, and Pb²⁺, respectively. These electrodes significantly reduce the dimensions of the conventional three electrode electrochemical cell to the microscale.

中文翻译：

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碳纳米管线电化学电池：重金属的检测

在这项工作中，电化学电池中的所有三个电极都是基于碳纳米管（CNT）线制造的。使用部分用聚苯乙烯薄涂层绝缘以定义微电极区域的CNT线作为工作电极；使用裸露的CNT线作为辅助电极。然后在纳米碳丝上电镀一层银，然后在氯化物溶液中进行阳极氧化，形成一层AgCl，从而制成了微准参比电极。与传统的液接型Ag | AgCl参比电极相比，涂有Ag | AgCl的CNT螺纹电极提供了稳定的电势。CNT线辅助电极提供的稳定电流可与Pt线辅助电极相媲美。该全CNT螺纹三电极电池已被评估为用于通过阳极溶出伏安法（ASV）同时测定痕量重金属离子的微传感器。汞柱²⁺，Cu ²⁺和Pb ²⁺被用作本研究的代表性系统。对于Hg 2 ⁺，Cu ²⁺和Pb ²⁺，在120 s沉积时间下计算得出的检测极限（基于3σ方法）分别为1.05、0.53和0.57 nM 。这些电极将传统的三电极电化学电池的尺寸显着减小到了微米级。