Highly Sensitive Detection and Removal of Lead Ions in Water Using Cysteine-Functionalized Graphene Oxide/Polypyrrole Nanocomposite Film Electrode

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• 作者：Rajesh Seenivasan ; Woo-Jin Chang ; Sundaram Gunasekaran
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 29, 2015
• 年：2015
• 卷：7
• 期：29
• 页码：15935-15943
• 全文大小：515K
• ISSN：1944-8252

文摘

We synthesized cysteine-functionalized graphene oxide (sGO) using carbonyldiimidazole as a cross-linker via amide and carbamate linkages. The sGO/polypyrrole (PPy) nanocomposite film was grown on the working electrode surface of a screen-printed electrode (SPE) via controlled one-step electrochemical deposition. The sGO/PPy-SPE was used to detect lead ions (Pb²⁺) in water by first depositing Pb²⁺ on the working electrode surface for 10 min at 鈭?.2 V, and then anodic stripping by differential pulse voltammetry (DPV). The DPV signals were linear in the ranges of 1.4鈥?8 ppb (R² = 0.994), 28鈥?80 ppb (R² = 0.997), and 280鈥?4鈥?00 ppb (R² = 0.990) Pb²⁺. The measurable detection limit of the sensor is 0.07 ppb (S/N = 3), which is more than 2 orders of magnitude below the 10 ppb threshold for drinking water set by the World Health Organization. The average removal efficiency of Pb²⁺ deposited on the electrode was 99.2% (S/N = 3), with relative standard deviation (RSD) of 3.8%. Our results indicate good affinity of sGO/PPy nanocomposite to Pb²⁺, which can be used to effectively adsorb and remove Pb²⁺ in water samples. Therefore, sGO/PPy nanocomposite we synthesized is useful for highly sensitive on-site and real-time monitoring of heavy metal ions and water treatment.