An Electrochemiluminescence Biosensor for the Determination of Mercury Ion via Dual-Amplification Strategy

Xuemei Fan, Shumin Wang, Zhejian Li, Yimeng Wang, Xinhui Fan, Lingmin Yu
2020 Journal of the Brazilian Chemical Society  
A novel dual-signal amplificatory electrochemiluminescence (ECL) deoxyribonucleic acid (DNA) biosensor was designed for the determination of Hg 2+ . One amplification unit was gold nanoparticles (AuNPs) modified on a glassy carbon electrode, and the other was single-stranded DNA (ssDNA) (with amino at the 3' terminal and thiol at the 5' terminal) labeled with a carboxylfunctionalized Ru@SiO 2 nanoparticles (Ru 1 @SiO 2 ) as a nanoprobe. The ECL biosensor was obtained through a strong
more » ... a strong gold-sulfur bond between Au on AuNPs modified electrode and thiol in the nanoprobe. In the presence of Hg 2+ , the ECL signal reduced because the T-Hg 2+ -T existed between the ECL nanoprobe and the complementary DNA (c-DNA), which exhibited a sensing platform for the detection of Hg 2+ . The results revealed that the reduced ECL intensity was linearly proportional to the logarithm of the Hg 2+ concentration in the range of 1.0 pmol L -1 -100 nmol L -1 with limit of detection 0.02 pmol L -1 . The proposed method was applied for the analysis of Hg 2+ in the river water and the results were in good agreement with that obtained by atomic fluorescence spectroscopy.
doi:10.21577/0103-5053.20200144 fatcat:4767jwsmnjestlfrqfvlkggoii