There is increasing evidence supporting a causal role of oxidatively damaged DNA in neurodegeneration during the natural aging process and neurodegenerative diseases such as Parkinson’s and Alzheimer’s. The presence of dopamine hydrochloride (DA), a kind of redox-active catecholamine neurotransmitters, coupled with catalytic ferric ions or copper could induce oxidatively DNA damage. DNA damage involves oxidation of guanine to 8-oxoguanine (8-oxoG) and DNA strand scission. It proceeds through the reactive oxygen species (ROS) generation. This paper proposed an electrochemical biosensor have investigated the role of Fe (III) and Cu (II)-catalyzed oxidation of dopamine to induce oxidatively generated DNA damage and its prevention. Incubation of DNA-modified electrode with DA solution containing Cu (II( or Fe(III) has been shown change in the electrochemical properties and the oxidative damage to the DNA. It was found that presence of Cu (II) and Fe(III) in solution caused damage to DNA. The inhibitory effect of glutathione (GSH) and ascorbic acid (AA) on the DA-mediated DNA damage has also been investigated using the biosensor. In The present work, a pretreated pencil graphite electrode (PGE) modified with multiwall carbon nanotubes (MWCNTs) and chitosa (CHIT) decorated with the ds-DNA were prepared as a sensor. DNA damage induced by radicals generated from the dopamine in the presence Of some transition metals. DNA damage was detected by using differential pulse voltammetry and electrochemical impedance spectroscopy using K 3 [Fe(CN) 6 ]/K 4 [Fe(CN) 6 ]. The change in the charge transfer resistance (R p ) and decrease in the intensity of the guanine and adenine oxidation signals after incubation of the DNA biosensor in the damaging solution for a certain time was used as indicators of DNA damage.
