Burcin Bozal-Palabiyik, Burcu Dogan-Topal, Abdolmajid Bayandori Moghaddam, Sibel A. Ozkan, Mahmood Kazemzad and Bengi Uslu* Pages 305 - 312 ( 8 )
Background: Nanomaterials have a significant role in improving the performance of electrochemical sensing systems. Unique physical and chemical properties have extended the application of nanomaterials in the fields of engineering, materials and biomedical science. In the last few years, these materials with unique properties have been preferred in the design of experimental approaches for the analysis of metal ions, proteins, biomarkers and pharmaceutical compounds. This paper reports preparation, characterization of two different nanomaterials and their electrochemical application on doublestranded calf-thymus DNA signals.
Methods: The multi-walled carbon nanotubes were functionalized with amine groups (MWCNTs-NH2) by employing the dielectric barrier discharge plasma treatment and then applied as MWCNTs- NH2/glassy carbon electrode. Moreover, the synthesized mesoporous silica MCM-41 was chemically amine functionalized and used as MCM-41-NH2/carbon paste electrode. For biosensor preparation, a thin layer of calf thymus double stranded deoxyribonucleic acid (ct-dsDNA) was immobilized over the modified electrodes.
Results: The influence of dsDNA immobilized substrate was investigated based on the electrochemical signals. While dsDNA/MCM-41-NH2/carbon paste biosensor showed a selective effect for guanine signals, the dsDNA/MWCNTs-NH2/glassy carbon biosensor presented electrocatalytic effect for dsDNA signals. Both dsDNA modified electrodes were employed to explore the interaction between the dsDNA and the anticancer drug etoposide (ETP) in aqueous solution through voltammetric techniques. By increasing the interaction time with ETP, the adenine peak current was quenched in the presence of MWCNTs-NH2 based glassy carbon electrode. Whereas, in the presence of MCM-41-NH2 based CP electrode, selective interaction with guanine occurred and oxidation peak intensity was diminished.
Conclusion: The selective effect of MCM-41-NH2 can be used when the studied substances give a signal with the same potential of adenine.
Functionalized nanomaterials, biosensor, deoxyribonucleic acid, multiwalled carbon nanotubes, mesoporous silica, electrochemistry.
Faculty of Pharmacy, Department of Analytical Chemistry, Ankara University, 06100 Tandogan-Ankara, Faculty of Pharmacy, Department of Analytical Chemistry, Ankara University, 06100 Tandogan-Ankara, Faculty of Engineering Science, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran, Faculty of Pharmacy, Department of Analytical Chemistry, Ankara University, 06100 Tandogan-Ankara, Materials and Energy Research Center, P.O. Box 14155-4777, Tehran, Faculty of Pharmacy, Department of Analytical Chemistry, Ankara University, 06100 Tandogan-Ankara