Biosensor based on In2O3 Electrolyte Gated Thin Film Transistor with Integrated On-Chip Gate Electrode

In this work, In2O3 electrolyte gated thin film transistors (In2O3-EGTFTs) with integrated on-chip gate electrode were investigated as a label-free biosensor. The In2O3 channel works as sensitive membrane and the on-chip gate electrode replaces reference electrode. The pH sensitivity of the device is 64 mV/pH with the deviation of 10 mV. The In2O3 channel was coated by streptavidin/neutravidin receptors to detect the target biomolecules of biotin. The streptavidin modified device presents an ultra-low working voltage (VG=0 V, VDS=50 mV) and the detection limit as low as 50 pg·mL-1. And the neutravidin modified device presents apparent detecting performance even in low biotin concentration of 50 fg·mL-1 under a working voltage of VG=2 V and VDS=50 mV. This work provides a high-performance biosensor device with low power consumption and simple structure that is easy to integrate and package.