Ultrasensitive Sensing of Hg2 and CH3Hg Based on the Fluorescence Quenching of Lysozyme Type VI-Stabilized Gold Nanoclusters

作者：Lin, Yen Hsiu; Tseng, Wei Lung^*

来源：Analytical Chemistry, 2010, 82(22): 9194-9200.

DOI：10.1021/ac101427y

This study presents a one-step approach to prepare lysozyme type VI-stabilized gold nanoclusters (Lys VI-AuNCs) for the ultrasensitive detection of Hg2 and CH3Hg based on fluorescence quenching. The optical properties and size of Lys VI-AuNCs are highly dependent on the concentration of Lys VI, which acts as both a reducing and a stabilizing agent. With an increase in the concentration of Lys VI, we observed a systematic blue shift in the fluorescence maxima, an increase in the quantum yields, and a reduction in the particle size. When using 25 mg/mL Lys VI as a reducing agent, the formed Lys VI-AuNCs (denoted as Au-631) were found to be highly stable in a high-concentration glutathione or NaCl. Additionally, the Au-631 were capable of sensing Hg2 and CH3Hg through the interaction between Hg2 /CH3Hg and Au on the Au surface; the limits of detection (LODs) for Hg2 and CH3Hg were 3 pM and 4 nM, respectively. The selectivity of this probe is more than 500-fold for Hg2 over any metal ions. As compared to bovine serum albumin-stabilized AuNCs, Au-631 provided an approximately 330-fold improvement in the detection of Hg2 . To the best of our knowledge, Au-631 not only provide the first example for detecting CH3Hg but also have the lowest LOD value for Hg2 when compared to other AuNC-based Hg2 sensors. Importantly, this probe was successfully applied to the determination of Hg2 and CH3Hg in seawater.

• 出版日期2010-11-15
• 单位中山大学