Simulation Studies on ZnO Nanoparticle Based FET Device for Possible Biosensing Applications

In this paper, a Field Effect Transistor (FET) having ZnO nanoparticles as the channel layer is simulated and proposed for possible biosensing applications. Based on simulations carried out using device simulation tool COGENDA TCAD, performance analysis in terms of threshold voltage, subthreshold slope, transconductance and on-off current ratio is measured. The structure under investigation is a bottom-gate FET device. The drain current flowing through the channel is controlled by the external potential applied at the gate terminal. The channel acts as a chemiresistive channel, whose conductivity changes on being electrostatically bound to certain biomolecule or protein. Based on its positive zeta potential, the electrostatic affinity of ZnO nanoparticles with certain proteins can be employed for specific detection of that protein. In addition, the simulated ZnO nanoparticles based FET device has dimensions favorable to be used as a biosensor along with scope of miniaturization. Hence, it can be stated that the proposed FET will be of great promise for future nanobiosensors, and if realized by proper fabrication, it may outperform the conventional sensors already in use for detection of biomolecules as well as for theranostic applications.