ABSTRACT
The optimal duration of the deposition process is about 5 min. The time dependence of the current, which represents the rate of hybridization, is well described (R2=0.99) by the diffusion-limited Langmuir equation (Equation 6) [30]
(6)
where kD is the surface binding rate (here the rate of hybridization of the SBP-labeled target to the electrode-bound probe), related to the rate of diffusional mass transport, and emax is the maximal surface concentration of enzyme, reached after hybridization of all possible probes that can hybridize. For a thin redox polymer film and neglecting diffusion of the substrate (H2O2 in the present case), the saturation current is given by Equation 7.
