ZnO Nanowire Field Effect Transistor for Biosensing: A Review

The last 19 years have seen intense research made on zinc oxide (ZnO) material mainly due to the ability of converting the natural n-type material into p-type. For a long time, the p-type state was impossible to attain and maintain. The review focuses on ways of improving the doped ZnO material which acts as a channel for nanowire field effect transistor (NWFET) and biosensor. The biosensor has specific binding which is called functionalisation achieved by attaching a variety of compounds on the designated sensing area. Reference electrodes and buffers are used as controllers. Top-down fabrication processes are preferred over bottom-up because they pave way for mass production. Different growth techniques are reviewed and discussed. Strengths and weaknesses of the FET and sensor are also reviewed.