Fully Transparent Field-Effect Biosensors

X. Du, G.S. Herman
Oregon State University,
United States

Keywords: biosensor, glucose monitoring, field-effect, IGZO

Summary:

Amorphous indium gallium zinc oxide (IGZO) field effect transistors (FETs) are a promising technology for a wide range of electronic applications including implantable and wearable biosensors. We have recently developed novel, low-cost printing methods to fabricate IGZO-FETs, with a wide range of form factors. Attaching self-assembled monolayers (SAM) to the IGZO backchannel allows us to precisely control surface chemistry and improve stability of the sensors. Functionalizing the SAMs with enzymes provides excellent selectivity for the sensors, and effectively minimizes interference from acetaminophen/ascorbic acid. We have recently demonstrated that a nanostructured IGZO network can significantly improve sensitivity as a sensing transducer, compared to blanket IGZO films. We will discuss reasons for improved sensitivity for the nanostructured IGZO, and demonstrate high sensitivity for glucose sensing. Finally, fully transparent glucose sensors have been fabricated directly on transparent catheters, and have been characterized by a range of techniques. These results suggest that IGZO-FETs may provide a means to integrate fully transparent, highly-sensitive sensors into contact lenses.