An Oligonucleotide-based Fluorescence Sensor for Mercury(II) in Aqueous Solutions

作者：Wu Huiwang; Liu Xueping; Jiang Jianhui; Shen Guoli; Yu Ruqin^*

来源：Chinese Journal of Chemistry, 2009, 27(8): 1543-1547.

DOI：10.1002/cjoc.200990260

• fluorescence sensor
• Hg(II) ion
• thymine
• FRET (fluorescence resonance energy transfer)

A highly selective fluorescence sensor was developed for Hg(II) ion detection in aqueous Solutions based on the selective binding of Hg(II) ions with a pair of thymine-thymine mismatch. The sensor consists of two DNA probes functionalized with a fluorophore (fluorescein, F) and a quencher (tetramethyl rhodamine, Q) moiety separately. This pair of DNA probes contains two pairs of thymine-thymine mismatches used to detect Hg(II) ions. In the presence of Hg(II) ions, thymine-Hg2 -thymine was formed between thymine residues of probes. From that, the interaction of the two DNA probes increased. Thus, the DNA probes formed a double-stranded structure. Both the fluorophore and quencher were brought close to each other leading to the fluorescence resonance energy transfer (FRET) between F and Q. Under the optimum conditions, the sensor was used to detect the Hg(II) ions from 50 to 1000 nmol.L-1 with a regression equation y=5281.13-1650.56 lg[Hg2 ] (R-2=0.985). The linear range covers 100 to 500 nmol.L-1, and the limit of detection (LOD) is 79 nmol.L-1. The disturbance of some co-existing metal ions was explored, and no significant fluorescence quenching in the presence of 1.0 mu mol-L-1 other metal ions was observed. The fluorescence sensor has good sensitivity and selectivity for Hg(II) ions providing a rapid, simple and low cost method for the detection of memcury(II) ions in aqueous solutions.

• 出版日期2009-8
• 单位湖南大学