Naphthalene diimide carrying four ferrocenyl substitutes as an electrochemical indicator of tetraplex DNA aiming at cancer diagnosis

Abstract

Naphthalene diimide carrying four ferrocenyl substituents, tFND1 and tFND2, were newly synthesized to expect the improved binding affinity for tetraplex DNA and specific electrochemical signal generation. tFND2 shows the 1:2 binding to tetraplex A-core DNA, which has a part of human telomere sequence based on circular dichroism spectra, and the current increase of tFND2 on the tetraplex DNA-immobilized electrode was 13.5-times higher than that on the single stranded DNA-immobilized electrode. When applied to an electrochemical telomerase assay (ECTA) for HeLa cell, tFND2 shows the quantitative change around 0.1–50 cells/μL and the detection limit of 0.1 cells/μL for HeLa cell