At Oregon State University researchers are working on integrating biosensors into contact lenses that may one day allow for non-invasive glucose testing, monitoring of various diseases, and tracking of pharmacokinetics of clinical compounds.
The technology relies on indium gallium zinc oxide (IGZO), a recently developed semiconductor that is already playing a large role in consumer electronics. It was used to make a transparent film of field-effect transistors that also contained deposits of glucose oxidase, an enzyme that reacts with glucose.
As the pH of the environment around the field-effect transistors changes, the amount of current flowing through them changes as well. Because glucose oxidase breaking down glucose affects pH levels, the current output of the transistors is indicative of the concentration of surrounding glucose.
So far the technology is yet to be tried on humans, but the transparent film is able to detect glucose concentrations at lower concentration than that found in tears, a promising sign.
Though noninvasive glucometry is a holy grail of medicine, this technology should also be useful in tracking other biomarkers besides glucose. Additionally, though the technology’s applications seem most exciting as part of contact lenses, it could also be implemented within all kinds of implants, instruments, and devices that interact with the body.