DISSERTATION

________________________________________________________________ Experimental Work
charge remains the same regardless of the presence of [Ru(NH3)6] 3+ the term nFAΓ0 can be
determined as the difference in the intercept at t = 0 from a Q-t 1/2 graph (Figure 5.11).
Figure 5.11. DNA coverage determination via chronocoulometry. Curves are shown for a
ssDNA/MCH-modified electrode in the absence (grey curve) or presence (green curve) of
[Ru(NH3)6] 3+ in solution.
Since it is assumed that each molecule of [Ru(NH3)6] 3+ binds to three phosphate groups from
the DNA backbone, the amount of DNA strands present on the electrode surface is then
calculated using the following equation:
Γ DNA = Γ 0 ( z m ) N A (5.17)
where z is the charge of the redox molecule and m is the number of phosphate groups at the
DNA strand.
126