Glucose biosensors based on layer-by-layer nano self-assembled ion-sensitive field-effect transistors

This paper demonstrates the fabrication and characterization of two types of glucose biosensors based on layer-by-layer self-assembled ion-sensitive field-effect transistors (ISFET). One glucose biosensor uses the self-assembled indium oxide (In₂O₃) nanoparticle thin film as the channel, while the other employs the self-assembled semiconducting polymer polyaniline (PANI) thin film as the channel. The self-assembled silicon dioxide (SiO₂) nanoparticle thin film serves as the gate dielectric for both types of ISFETs. For the In₂O₃ ISFET, the field-effect mobility is 38.66 cm²/Vs, and the sensitivity to glucose is 2.125 μA/mM. For the PANI ISFET, the mobility is 14.31 cm² /Vs, and the sensitivity to glucose is 0.738 μA/mM. The results demonstrate that nanoparticles and polymers are very promising materials for the applications to low-cost biosensors.