A novel electrochemical method to detect mercury (II) ions

作者：Miao Peng; Liu Lei; Li Yun; Li Genxi^*

来源：Electrochemistry Communications, 2009, 11(10): 1904-1907.

DOI：10.1016/j.elecom.2009.08.013

• Mercury ions
• Gold nanoparticles
• Thiolated oligonucleotides
• Thymine-Hg(2+)-thymine complex
• Cyclic voltammograms

A novel and sensitive electrochemical method for determination of mercury (II) ions (Hg(2+)) based on the formation of thymine-Hg(2+)-thymine complexes and gold nanoparticle-mediated signal amplification is reported. Two 5' end thiolated complementary oligonucleotides containing six strategically placed thymine-thymine mistakes were introduced in this work. One of the two oligonucleotides was immobilized on a gold electrode and the other one on gold nanoparticles (AuNPs). Due to six thymine-thymine mistakes the two oligonucleotides were not able to be hybridized, so AuNPs could not be immobilized onto the electrode surface after the electrode was immersed in the DNA-AuNPs solution. However, if Hg(2+) existed, T-Hg(2+)-T complexes could be formed and AuNPs could be immobilized onto the electrode surface. Meanwhile, large numbers of [Ru(NH(3))(6)](3+) molecules as electrochemical species could be localized onto the electrode surface. The Hg(2+) detection limit of this assay could be as low as 10 nM, which is the US Environmental Protection Agency (EPA) limit of Hg(2+) for drinkable water. This method is proven to be simple, convenient, high sensitive and selective.

• 出版日期2009-10
• 单位上海大学; 南京大学