Electrochemical Recognition of Biomolecule Through DNA Homogenous Hybridization Based on Host-guest Recognition Technique

Electrochemical DNA biosensor with high sensitivity of homogenous hybridization was fabricated on the basis of host-guest recognition between β-cyclodextrin (β-CD) and m-toluic acid (mTA). β-CD, as the host molecule, was electropolymerized on the poly(N-acetylaniline)-modified glassy carbon electrode, and mTA, was labeled on the probe DNA as the guest through acid-amine condensation reaction. Two intercalators were used as electrochemical indicators to detect DNA hybridization:methylene blue (MB) and daunorubicin (DNM). The electrochemical signals of MB were linear in the range of complementary DNA from 2.0 × 10−12 M to 2.0 × 10−10 M with a detection limit of 7.6 × 10−13 M. The electrochemical response of DNM was linear with the concentrations of complementary from 1 × 10−12 M to 1 × 10−9 M with a detection limit of 6.0 × 10−13 M. This DNA biosensing technique exhibited excellent reproducibility and stability.

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