ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 49, Number 4
JKCSEZ 49(4)
August 20, 2005 

Glassy carbon(GC) electrodes modified by adding a poly-[Ru(v-bpy)₃]²⁺ film of a transition metal complex were prepared in order to detect guanine and ds-DNA and the chemical damage caused to these molecules by the known damage inducing agents, toluene and styrene oxide. The redox response of the surface immobilized polymeric film was used as analytical signal. The catalytic peak current at the modified electrode was 6 times higher than that observed at bare GC electrode. The second-order rate constant of the modified electrode was 0.26 M^-1s^-1 as 4.5 times higher than that of the bare GC electrode. The calibration curve, i.e. log of the surface coverage-normalized redox response vs log[guanine], exhibited excellent correlation (r≥0.99) for guanine concentrations ranging from 1.0×10^-7to 1.0×10^-3 M. The quantity of adsorbed ds-DNA on the modified electrode was 3.96×10^-6 gcm^-2. The catalytic peak current of the adsorbed ds-DNA was 6 times larger than the modified electrode alone. The ds-DNA incorporated on the electrode surface was chemically damaged 2% in the case of styrene oxide and 9% in the case of toluene.