Biochemical Responses of Nano-Pillar Gate Field-Effect Devices

We have developed biochemical field effect devices with nano-pillar array structure on the gate. The pH responses of the field effect device with nano-pillar structure were nonlinear. It seems that the plasma treatment of the Si₃N₄ surface as well as a mixed composition of Si₃N₄ and SiO₂ may play an important role for the nonlinearity of the pH response. Oligonucleotide probes with fluorescent label were immobilized on the surface of the nano-pillar gate structure. The fluorescent intensity of the device with nano-pillar structure was stronger than that of the flat gate device. The increase of the fluorescent intensity for the nano-pillar device could be explained by the increase of the number of immobilized oligonucreotide probes because of the larger surface area. We can therefore expect highly sensitive detection of biomolecules with the nano-pillar gate field effect devices.