A DNA hydrogel gated organic field effect transistor

In this work, we fabricated bulk DNA hydrogels that we grew onto the gold gate electrode of an electrolyte-gated organic field-effect transistor and we demonstrated that such a device kept the electrical characteristics which were expected from electrolyte-gated devices. We also demonstrated that the transistor can work without external electrolyte, as a solid-state hydrogel-gated device. As a first proof-of-concept, a vascular endothelial growth factor (VEGF)-specific DNA aptamer was incorporated into the DNA hydrogel and the dependence of the drain current of the transistor upon binding with the target VEGF was compared to the current response upon addition VEGF onto a similar hydrogel without aptamer. This is the first reported example of application of a bulk functional DNA hydrogel as solid-state electrolyte in an electrolyte-gated Organic Field-Effect Transistor (OFET).