Electrochemical Behavior of Daunorubicin at DNA‐MWCNT Bioconjugates Modified Glassy Carbon Electrodes

Abstract

The DNA‐multiwalled carbon nanotube (MWCNT) bioconjugates were prepared by dispersing MWCNTs in calf thymus single‐stranded (ss‐) or double‐stranded (ds‐) DNA aqueous solution. The electrochemical behaviors of daunorubicin (DNR) at ssDNA and dsDNA‐MWCNT bioconjugates‐modified glassy carbon electrodes (GCEs) were studied by cyclic voltammetry, respectively. The aromatic nucleotide bases in ssDNA interact with the sidewalls of MWCNTs via π‐stacking, leaving the deoxyribose backbones exposed to solution, which causes the surface of the MWCNT highly negatively charged. Therefore, the interaction between DNR and ssDNA‐MWCNT was only electrostatic. In addition to electrostatic interaction, DNR can interact with dsDNA through intercalating into base pairs and binding to minor grooves, which makes the electrochemical behavior of DNR at dsDNA‐MWCNT different from that at ssDNA‐MWCNT bioconjugates‐modified GCEs.

Keywords:

• DNA
• carbon nanotube
• daunorubicin
• electrochemistry

Acknowledgments

This work was supported by the National Science Fund for Distinguished Young Scholars (No. 20025311) and National Natural Science Foundation of China (Grant Nos. 30170268; 29773034; 39770220).