Thiacalixarene Covalently Functionalized Multiwalled Carbon Nanotubes as Chemically Modified Electrode Material for Detection of Ultratrace Pb2+ Ions

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• 作者：Li Wang ; Xiaoya Wang ; Guosheng Shi ; Cheng Peng ; Yihong Ding
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：December 18, 2012
• 年：2012
• 卷：84
• 期：24
• 页码：10560-10567
• 全文大小：502K
• 年卷期：v.84,no.24(December 18, 2012)
• ISSN：1520-6882

文摘

This paper presents the preparation of novel thiacalixarene (TCA) covalently functionalized multiwalled carbon nanotubes (MWCNTs) and an enhanced differential pulse anodic stripping voltammetric procedure for the determination of trace amounts of Pb²⁺ ions, which relies on the selective accumulation of the metals at a TCA-MWCNT-modified glassy carbon electrode. Through a combination of thiacalixerene鈥檚 excellent selective recognition and the outstanding electronic properties of MWCNTs, this electrode material shows excellent selectivity and high sensitivity for electrochemical detection of Pb²⁺ ions. The stripping response is highly linear (R = 0.999) over a Pb²⁺ concentration range of 2 脳 10^鈥?0 to 1 脳 10^鈥? mol/L, and the limit of detection is 4 脳 10^鈥?1 mol/L. Furthermore, the determination of Pb²⁺ (10^鈥? mol/L) in the presence of an equal amount of interfering Sn²⁺ ions yielded well-separated signals. To understand the molecular interaction mechanism between the TCA molecules and metal ions (Pb²⁺ and Sn²⁺), theoretical computations were performed. The results demonstrate that the Pb²⁺/Sn²⁺ ions could stably adsorb onto the TCA molecules, and there is significant electron delocalization between Pb²⁺/Sn²⁺ and sulfur atoms in the TCA molecule.