Ion-selective electrodes using carbon nanotubes as ion-to-electron transducers
Ion-selective electrodes using carbon nanotubes as ion-to-electron transducers
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DOI：
10.1021/ac071156l
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发表时间：
2008-02-15
影响因子：
7.4
通讯作者：
Xavier Rius, F.
中科院分区：
文献类型：
--
作者：
Crespo, Gaston A.;Macho, Santiago;Xavier Rius, F.
本研究开发了一种基于单壁碳纳米管网络转导层的新型全固态离子选择电极。碳纳米管促进非均相之间电子转移的非凡能力使得电活性聚合物或任何其他离子到电子转移促进剂的存在变得不必要。利用环境扫描电镜和电化学阻抗谱对新型换能器层进行了表征。采用电流逆转计时电位法检测了新型固体接触电极电位的稳定性，采用电位水层法检测了界面水膜对电极电位稳定性的影响。新电极的性能是通过含有著名的万霉素离子载体的离子选择膜来测定K+来评估的。新电极具有58.4 mV/ 10年的纳恩斯蒂斜率，4个对数单位的动态范围，选择性和检出限与其他固体接触电极相当。较短的响应时间（高于10(-5.5)M的活动小于10秒）和数天内信号的稳定性使这些新电极非常有希望实现真正的小型化。
This study developed a new type of all-solid-state ion-selective electrode based on a transducing layer of a network of single-walled carbon nanotubes. The extraordinary capacity of carbon nanotubes to promote electron transfer between heterogeneous phases made the presence of electroactive polymers or any other ion-to-electron-transfer promoter unnecessary. The new transducer layer was characterized by environmental scanning electron microscopy and electrochemical impedance spectroscopy. The stability of the electrical potential of the new solid-contact electrode was examined by performing current-reversal chronopotentiometry, and the influence of the interfacial water film was assessed by the potentiometric water layer test. The performance of the new electrode was evaluated by determining K+ with an ion-selective membrane that contained the well-known valinomycin ion carrier. The new electrode had a Nernstian slope (58.4 mV/decade), dynamic ranges of four logarithmic units, and selectivities and limits of detection comparable to other solid-contact electrodes. The short response time (less than 10 s for activities higher than 10(-5.5) M) and the stability of the signal over several days makes these new electrodes very promising candidates for attaining true miniaturization.