Highly sensitive determination of DNA via a new type of electrochemical zirconium signaling probe

Abstract

A fast and simple strategy for the detection of DNA based on a new type of electrochemical Zr(IV) signaling probe is reported. Briefly, this DNA biosensor was fabricated by covalently coupling the amino groups of peptide nucleic acid (PNA) probes with aldehyde groups on the surface of a glassy carbon electrode (GCE), for specifically capturing target DNA (tDNA). After this, Zr(IV) probes were attached to the phosphate groups of DNA directly with strong coordination interaction, and stoichiometrically labeled Zr(IV) probes can be detected via differential pulse voltammetry (DPV). Under optimized conditions, this strategy showed a good linear response from 0.01 nM to 100 nM tDNA, and the detection limit was 0.81 pM (R² = 0.998). Moreover, this DNA biosensor is also successfully applied to the DNA detection in serum samples with satisfactory results and shows great potential in clinical analysis.