The device, called OcuCheck, works by measuring levels of vitamin C in the fluids that coat or leak from the eye. The sensor could speed efforts to determine the extent of eye injuries at accident sites, in rural areas lacking ophthalmology specialists or on the battlefield, the researchers said.
“The sensor takes advantage of the fact that the ocular tear film – the viscous fluid that coats the eyeball – contains low levels of ascorbic acid, which is just vitamin C, while the interior of the eye contains much higher levels. So the concept is, if there is severe damage to the eye that penetrates deeply, the ascorbic acid will leak out in high concentration” author said.
At present, those with eye injuries must find their way to a hospital to have their injuries assessed. The process is often complicated, time-consuming and imprecise. No current techniques for assessing eye injuries involve measurements of ascorbic acid, author said. “So this is a one-of-a-kind approach.”
The new sensor uses graphene platelets that are layered 1 nanometer thick on filter paper. Upper layers include a unique polymer that interacts with the graphene; gold electrodes; and ascorbate oxidase, an enzyme that binds to ascorbic acid.
“The idea is that the moment that the ascorbic acid comes in and binds to the ascorbate oxidase, it will pull the polymer out of its interaction with the graphene,” changing the sensor’s electrical properties, author said.
In tests with clinical samples from 16 patients undergoing eye surgery, the team found that their sensor could – with high sensitivity, accuracy and specificity – detect a range of ascorbic acid concentrations.
OcuCheck has not yet been tested on samples from trauma patients.