Immobilization of Target-Bound Aptamer on Field Effect Transistor Biosensor to Improve Sensitivity for Detection of Uncharged Cortisol

Field effect transistor (FET) biosensors are capable of detecting various biomolecules, although challenges remain in the detection uncharged molecules. In this study, cortisol was demonstrated by interfacial design using a technique to immobilize target-bound aptamers. The aptamers, which formed higher-order structure than target-unbound expanded distance between adjacent aptamers and reduced steric hindrance conformational change. density-controlled efficiently induced their changes with binding, resulted improvement sensitivity FET biosensors.