A new electrochemical biosensor based on telomeric G-quadruplex DNA: In silico and experimental study of dihydropyridine derivatives potential effect on telomerase inhibition

- G-quadruplex DNA is self-assembled on the electrode.
- 1,4-Dihydropyridine derivatives were introduced as the ligands by anti-cancer potential.
- The discrimination between quadruplex DNA and duplex DNA has now been reported for 1,4-dihydropyridine ligands.
- EIS technique could detect ligand affinity with high sensitivity.
- The proposed method could be expanded readily for detecting other drugs.

The electrochemical biosensor was prepared by modification of a glassy carbon electrode (GCE) with Au nanoparticles (AuNPs), G-quadruplex DNA (G4DNA) and i-motif DNA (C4DNA or i-DNA) structures to investigate of telomerase enzyme inhibitors. SH-G4DNA and SH-i-DNA were linked to the modified electrode by AuNPs-S binding. This platform was used to study the quadruplex DNA/ligand interaction. The interaction of different ligands with quadruplex DNA was studied in a 5.0 mM [Fe(CN)6]3 −/4 − solution as a redox probe at the surface of these biosensors, using the electrochemical impedance spectroscopy (EIS) technique. The resistance of charge transfer (Rct) values was increased by increasing the concentration of ligand due to the quadruplex DNA/ligand interaction. Under the optimum conditions, the observations revealed that 1,4-dihydropyridine (1,4-DHP) derivatives had a good affinity toward the quadruplex DNA structures in the concentration range of 5.0-700.0 μM. The selectivity was examined using different double-stranded (ds-DNA) sequences.

Electrochemical biosensor based on telomeric G-Quadruplex DNA for investigation of telomerase enzyme inhibitors as a potential drug target by electrochemical impedance spectroscopy.190