鈥淭urn-on鈥?Fluorescence Detection of Lead Ions Based on Accelerated Leaching of Gold Nanoparticles on the Surface of Graphene

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• 作者：Xiuli Fu ; Tingting Lou ; Zhaopeng Chen ; Meng Lin ; Weiwei Feng ; Lingxin Chen
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：February 22, 2012
• 年：2012
• 卷：4
• 期：2
• 页码：1080-1086
• 全文大小：378K
• 年卷期：v.4,no.2(February 22, 2012)
• ISSN：1944-8252

文摘

A novel platform for effective 鈥渢urn-on鈥?fluorescence sensing of lead ions (Pb²⁺) in aqueous solution was developed based on gold nanoparticle (AuNP)-functionalized graphene. The AuNP-functionalized graphene exhibited minimal background fluorescence because of the extraordinarily high quenching ability of AuNPs. Interestingly, the AuNP-functionalized graphene underwent fluorescence restoration as well as significant enhancement upon adding Pb²⁺, which was attributed to the fact that Pb²⁺ could accelerate the leaching rate of the AuNPs on graphene surfaces in the presence of both thiosulfate (S₂O₃2鈥?/sup>) and 2-mercaptoethanol (2-ME). Consequently, this could be utilized as the basis for selective detection of Pb²⁺. With the optimum conditions chosen, the relative fluorescence intensity showed good linearity versus logarithm concentration of Pb²⁺ in the range of 50鈥?000 nM (R = 0.9982), and a detection limit of 10 nM. High selectivity over common coexistent metal ions was also demonstrated. The practical application had been carried out for determination of Pb²⁺ in tap water and mineral water samples. The Pb²⁺-specific 鈥渢urn-on鈥?fluorescence sensor, based on Pb²⁺ accelerated leaching of AuNPs on the surface of graphene, provided new opportunities for highly sensitive and selective Pb²⁺ detection in aqueous media.

Keywords:

lead ions; fluorescence detection; graphene; gold nanoparticles; leaching