Solid substrate-room temperature phosphorimetry for the determination of trace lead using p

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• 作者：Yang Tianlong ; Liu Zhenbo ; Liu Jiaming ; Liu Haizhu ; Huang Yahong ; Liu Jianqin ; Chen Xuebing ; Zhao Yibing
• 关键词：Lead ; Multi-wall carbon nanotubes ; p-Nitro-phenyl-fluorone ; Tween-80 ; Solid substrate-room temperature phosphorimetry
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：72
• 期：1
• 页码：156-164
• 全文大小：731 K

文摘

The structures of multi-wall carbon nanotubes (MWNTs) were modified by H₂SO₄–HNO₃ and H₂SO₄–H₂O₂, respectively. The corresponding products were water-soluble MWNTs-A and MWNTs-B. According to the experiment, it was found that MWNTs-B could emit stable solid substrate-room temperature phosphorescence (RTP) on the surface of paper with Ag⁺ as perturber. Under the conditions of 70 °C and 15 min, MWNTs-B can react with Tween-80 and p-nitro-phenyl-fluorone (R) to form R-MWNTs-B–Tween-80 micellae compound, which could emit RTP of R and MWNTs-B on the surface of paper, respectively. Pb²⁺ could cause the RTP of R and MWNTs-B enhanced sharply, respectively. ΔI_p is directly proportional to the content of Pb²⁺. A new solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace Pb²⁺ has been established based on R-MWNTs-B–Tween-80 micellae compound containing double luminescent molecule. The detection limit of this method were 0.035 ag Pb²⁺ spot⁻¹ (8.8 × 10⁻¹⁷ g Pb²⁺ ml⁻¹, MWNTs-B) and 0.028 ag Pb²⁺ spot⁻¹ (7.1 × 10⁻¹⁷ g Pb²⁺ ml⁻¹, R). This method is of high sensitivity, good selectivity, high precision and accuracy. It could be applied to determine trace Pb²⁺ in serum samples at wavelength of 453.7/623.0 nm (R) or 475.9/645.0 nm (MWNTs-B) with satisfactory results, showing that SS-RTP has flexibility and utility value. Simultaneously, this method can be used to diagnose human diseases. The reaction mechanism for the determination of trace Pb²⁺ by SS-RTP based on R-MWNTs-B–Tween-80 micellae compound containing double luminescent molecule was also discussed.