Color-changing sensor detects signs of eye damage in tears

A new point-of-care rapid-sensing device can detect a key marker of eye injury in minutes – a time frame crucial to treating eye trauma.

University of Illinois researchers developed a gel laden with gold nanoparticles that changes color when it reacts with a teardrop containing ascorbic acid, released from a wound to the eye. In a new study published in the journal Biosensors and Bioelectronics, the researchers used the sensor, called OjoGel, to measure ascorbic acid levels in artificial tears and in clinical samples of fluid from patients’ eyes.

“We expect a significant potential impact of this biosensor for evaluating the eye in post-surgical patients as well as trauma patients,” said study leader Dipanjan Pan, a University of Illinois professor of bioengineering and the Carle Illinois College of Medicine.

Pan’s group collaborated with Dr. Leanne Labriola, an ophthalmologist at Carle Foundation Hospital in Urbana, to develop OjoGel.

“OjoGel technology may allow for faster identification of serious eye injuries,” Labriola said. “With a rapid point-of-care device such as this, anyone in an emergency department could perform a test and know within minutes if the patient needs urgent surgery to save their vision.”

Previous work by the group found that ascorbic acid concentration in tears is a good measure for determining extent of injury to the eye. Ascorbic acid, also known as vitamin C, is found in high concentrations in the fluid inside the eye, called aqueous humor, but normally has very low concentration in tears.