Analytical Sciences

Electrogenerated Chemiluminescence Detection of Mercury(II) Ions Based on DNA Probe Labeled with Ruthenium Complex

Yaping LI

Department of Chemistry and Chemical Engineering, Ankang University, Ankang 725000, P. R. China

A novel mercury(II) ion (Hg²⁺) biosensor with electrogenerated chemiluminescence (ECL) detection using tris(2,2′-bipyridyl) ruthenium derivatives (ruthenium complex) as labeling was developed in the prescent work. One thymine (T)-rich single-strand DNA (ssDNA) labeled with a ruthenium complex was taken as an ECL probe. When the other T-rich capture ssDNA was self-assembled onto the surface of a gold electrode with a thiol group, and then hybridized with the ECL probe to form double-strand DNA (dsDNA) structures in the presence of Hg²⁺, a strong ECL response was electrochemically generated. The ECL intensity was linearly related to the concentration of Hg²⁺ in the range from 1.0 × 10⁻⁶ to 1 × 10⁻⁹ M with a detection limit of 3.0 × 10⁻¹⁰ M. The relative standard deviation was 4.1% at 1.0 × 10⁻⁷ M Hg²⁺ (n = 5). This work demonstrates that the combination of the strongly binding T-rich DNA to Hg²⁺ with the highly sensitive ECL technique to design an ECL Hg²⁺ biosensor is a great promising approach for the determination of metal ions.

J-STAGE: View this article in J-STAGE