Pseudo-polyferrocene coating of double stranded DNA with ferrocenylnaphthalene diimide and its application for electrochemical gene detection

Abstract

Ferrocenylnaphthalene diimide derivatives (FND-1-FND-3) can intercalate into double stranded DNA (dsDNA) by a threading mode every two base pairs, resulting in the arrangement of many ferrocene molecules in the major and minor grooves of dsDNA. The pseudo-polyferrocene array templated to dsDNA thus obtained is expected to serve as a new material for nanotechnology including electrochemical gene detection. Since the pseudo-poly-ferrocene array formed on the electrode is analyzed electrochemically, the target gene can be detected by hybridization with a DNA probe-immobilized, electrode and by the ferrocenylnaphthalene diimide binding. Ferrocenylnaphthalene diimide-based electrochemical hybridization assay established in the author's group enabled rapid and highly sensitive detection of target DNA or RNA. This system can be further extended to a field where the single nucleotide polymorphism (SNP) analysis is feasible not only for polymerase chain reaction (PCR) products but also for genomic DNA taken from human white blood cells. This system could also be used for the detection of dsDNA on the DNA chip electrochemically, especially for visualization of the DNA chips by scanning electrochemical microscopy (SECM). Electrochemical DNA chips harboring multiple electrodes on a small substrate are becoming important for gene diagnosis and related purposes because of its simplicity, high sensitivity and low cost.