Biosensor Based on In₂O₂ Electrolyte Gated Thin Film Transistor With Integrated On-Chip Gate Electrode

In this work, In
₂
O
₃
electrolyte gated thin film transistors (In
₂
O
₃
-EGTFTs) with integrated on-chip gate electrode were investigated as a label-free biosensor. The In
₂
O
₃
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 In
₂
O
₃
channel was coated by streptavidin/neutravidin receptors to detect the target biomolecules of biotin. The streptavidin modified device presents an ultra-low working voltage (
$\text{V}_{\text{G}}=0$
V,
$\text{V}_{\text{DS}}=50$
mV) and the detection limit as low as 50 pg
$\cdot $
mL
$^{-1}$
. And the neutravidin modified device presents apparent detecting performance even in low biotin concentration of 50 fg
$\cdot $
mL
$^{-1}$
under a working voltage of
$\text{V}_{\text{G}}=2$
V and
$\text{V}_{\text{DS}}=50$
mV. This work provides a high-performance biosensor device with low power consumption and simple structure that is easy to integrate and package.