Figure 5.

Schematic representation and numerical solution of the NLER model. (a) The surface region is rich in NA probes (blue) immobilized on the copolymer coating (shaded area) and hence provides a negative net charge, which further increases upon hybridization with the target strands (dark red). The electrostatic potential is approximated by a step function having a value lower than that of the bulk solution up to a distance h from the RPI solid surface. (b) Fraction of hybridized probes at equilibrium and (c) kinetic rate computed for different surface densities of probes, from 10¹⁰ mm⁻² (blue) to 10¹¹ mm⁻² (red). The curves were computed with fixed kinetic parameters k_on⁰ = 2.3 × 10⁻⁴ nM⁻¹ s⁻¹ and k_off = 7.2 × 10⁻⁴ s⁻¹ and for Γ = γs_p, with γ = 2 × 10⁻¹¹ mm². To see this figure in color, go online.