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

Abstract 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.