Rapid, Selective, and Ultrasensitive Fluorimetric Analysis of Mercury and Copper Levels in Blood Using Bimetallic Gold鈥揝ilver Nanoclusters with 鈥淪ilver Effect鈥?Enhanced Red Fluorescence

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• 作者：Ning Zhang ; Yanmei Si ; Zongzhao Sun ; Lijun Chen ; Rui Li ; Yuchun Qiao ; Hua Wang
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：December 2, 2014
• 年：2014
• 卷：86
• 期：23
• 页码：11714-11721
• 全文大小：596K
• ISSN：1520-6882

文摘

Bimetallic alloying gold鈥搒ilver nanoclusters (Au-AgNCs) have been synthesized by a one-pot biomineralization synthesis route at a vital molar ratio of Au/Ag precursors in the protein matrix. Unexpectedly, the prepared Au-AgNCs could exhibit dramatically enhanced red fluorescence, which is about 6.5-fold and 4.7-fold higher than that of common AuNCs and core鈥搒hell Au@AgNCs, respectively. A rapid, selective, and ultrasensitive fluorimetric method has thereby been developed using Au-AgNCs as fluorescent probes toward the separate detections of Hg²⁺ and Cu²⁺ ions in blood. The interactions of Au-AgNCs with Hg²⁺ and Cu²⁺ ions were systematically characterized by microscopy imaging, UV鈥搗is, and fluorescence measurements. It is demonstrated that the 鈥渟ilver effect鈥?gives the Au-AgNCs probes not only greatly enhanced red fluorescence but also the strong capacity to specifically sense Cu²⁺ ions in addition to improved response to Hg²⁺ ions. Moreover, aided by a Cu²⁺ chelating agent, exclusive detection of Hg²⁺ ions could also be expected with the coexistence of a high level of Cu²⁺ ions, as well as reversible Cu²⁺ analysis by restoring the fluorescence of Au-AgNCs. Additionally, Au-AgNCs with strong red fluorescence could facilitate fluorimetric analysis with minimal interference from blood backgrounds. Such an Au-AgNCs-based fluorimetric method can allow for the selective analysis of Hg²⁺ and Cu²⁺ ions down to 0.30 nM and 0.60 nM in blood, respectively, promising a novel detection method to be applied in the clinical laboratory.