DISSERTATION

_____________________________________________________________ Results and Discussion
preparation. Therefore, the proposed method may become a new standard DNA immobilization
procedure to obtain desired surface coverages in a very short time as a prerequisite for the
development of highly sensitive and reproducible DNA hybridization assays with
electrochemical read-out.
Figure 3.30. Reproducibility of the potential-assisted immobilization method. Data
obtained from EIS measurements for ssDNA/MCH-modified electrodes by fitting Nyquist
plots to a [R(Q[RW])] equivalent circuit. The pulse profile for DNA immobilization was
performed for 15 min using a 10 ms pulse duration. The black dashed line represents the
average fitted Rct value for the MCH-modified electrode. Error bars represent the
standard deviation between measurements (n > 3). Figure adapted from ref. 5 .
3.3 Importance of controlling the surface 66