DISSERTATION

________________________________________________________________ Experimental Work
V (vs. Ag/AgCl/3 M KCl) potential pulse profile with 10 ms pulse duration, for 5 or 30 s. Upon
desorption, the electrode was rinsed with the same buffer and water.
5.7 Preparation of DNA sensors
5.7.1 ssDNA immobilization via incubation
Immobilization of ssDNA via incubation was done immediately after cleaning and
characterization of a gold electrode as explained in Chapter 5.3. The electrode was placed in an
Eppendorf tube containing 200 μL of ssDNA solution (1 μM in 10 mM PB, 450 mM K2SO4)
and kept in a thermo-mixer (HTC BioTech, Germany) at 37 ºC. The electrode was sealed within
the tube using parafilm to prevent solution evaporation. The duration of the immobilization
procedure depended on the desired DNA coverage. Afterwards, the electrode was thoroughly
rinsed with the immobilization buffer (10 mM PB with 450 mM K2SO4) and water to remove
any loosely bound ssDNA.
5.7.2 Potential-assisted ssDNA immobilization
Figure 5.5. Electrochemical setup used for potential-assisted sensor preparation.
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