Figure 3: Hybridization of DNA on PNA-grafted, Au-decorated ultralong SWNT-FET. (a) Confocal micrograph of the Au-decorated, PNA grafted ultralong SWNT after the hybridization of Cy-3 labeled target DNA. Inset shows an optical microscope image of the device, and the white arrow indicates Au-decorated ultralong SWNT. (b) Evolution of electrical characteristics upon hybridization at = 1 V. Clear decrease of conductance and negative shift of gate threshold voltages observed upon hybridization.