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

AUTOR(ES)
FONTE

J. Braz. Chem. Soc.

DATA DE PUBLICAÇÃO

2020-12

RESUMO

A novel dual-signal amplificatory electrochemiluminescence (ECL) deoxyribonucleic acid (DNA) biosensor was designed for the determination of Hg2+. 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 carboxyl-functionalized Ru@SiO2 nanoparticles (Ru1@SiO2) as a nanoprobe. The ECL biosensor was obtained through a strong gold-sulfur bond between Au on AuNPs modified electrode and thiol in the nanoprobe. In the presence of Hg2+, the ECL signal reduced because the T-Hg2+-T existed between the ECL nanoprobe and the complementary DNA (c-DNA), which exhibited a sensing platform for the detection of Hg2+. The results revealed that the reduced ECL intensity was linearly proportional to the logarithm of the Hg2+ 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 Hg2+ in the river water and the results were in good agreement with that obtained by atomic fluorescence spectroscopy.

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