DNA sensing
using MB as a DNA intercalator and a three-electrode
system. (A) Changes in cyclic voltammograms in 50 mM PBS (pH 7.4)
containing 100 mM KNO3 after sequential modification with
pDNA and MCH on a bare gold electrode. (B) Cyclic voltammograms obtained
with 20, 100, 500, and 1000 μM MB and a bare gold electrode
as the working electrode. (C) Cyclic voltammograms after incubating
1, 5, or 10 μM tDNA and 100 μM MB on the gold electrode
with immobilized pDNA and MCH. (D) Dependence of the reduction peak
current in panel C on tDNA concentration (CtDNA) (n = 3). The red circles and error bars indicate
the averages and standard deviations. All cyclic voltammograms were
obtained at a scan rate of 50 mV/s.