Control experiments to confirm a covalent bonding of DNA. In (a), a typical fluorescence image of a silanized and biofunctionalized nanowire is shown. In (b), an image of a nanowire is shown that was treated the same way, but leaving out the silanization step and using DNA without a 5'-amino linker. In (c), the fluorescence intensities of various control samples are compared. In (d), a comparison of a sample with GOPS and a sample without GOPS rinsed in Tris-HCl buffer solution for different periods of time is presented.