Designing anthraquinone-pyrrole redox intercalating probes for electrochemical gene detection

The real-time quantitative electrochemical monitoring of nucleic acid amplification through PCR is a promising renowned methodology to detect pathogenic DNAs. In this work, anthraquinone-pyrrole derivatives based redox intercalating probes (AP probes: AP1, AP2) have been designed, synthesized, characterized and successfully demonstrated in real-time like quantitative PCR. The rationally designed AP probes exhibited excellent DNA binding abilities and electrochemical behaviors. The binding parameters such as binding constant, binding site size and diffusion coefficient were estimated which were comparable to literature reports. Besides, the AP probes are highly stable under PCR thermal conditions and did not inhibit PCR. Therefore, a real-time like quantification of DNA amplification was demonstrated to quantify the initial copy number of target genes. The probe AP2 has excellent ability to detect ~103 copies of target tpc DNA with good sensitivity. The AP probes are metal-free, easily synthesizable, non-toxic, thermally stable and feasible for miniaturized PCR chips.