Figure 4.

(A) Optical images of a biosensor chip containing an array of nine interdigitated electrode (IDE) pairs that were fabricated to demonstrate the application of ND seeding layer for chemically stable covalent linkage of antibodies to electrodes. Each IDE contained 60 finger pairs with each finger 9 μm wide and spaced 9 μm apart. (B) Representative plot of real versus imaginary part of the impedance measured in deionized water on an IDE before and after ND seeding. (C) Representative plot of impedance magnitude and phase plotted against frequency as obtained on an IDE exposed to solutions with different electrical conductivity.