Figure 1.

(A) The effect of charging a gold surface in 10 mM sodium perchlorate electrolyte on the SPR data for same gold substrate at a series of applied potentials (0, 200, 400, and 600 mV). For clarity, only a portion of the full reflectance curves are shown. (B) Potential dependence of the complex dielectric constants (real, ɛ_r, and imaginary, ɛ_i, components) of the gold, calculated by fitting the full SPR reflectance curves (see text for details). The arrows indicate the potentials at which hybridization experiments were undertaken.