Licking a Tootsie roll sensor to monitor health

Previous researchers have indicated that simple measurements of a person's salivary salt and electrolyte content could be appropriate for managing some conditions.

Researchers wanted to repurpose unconventional and widely available materials, including electrically conductive soft candies, into an easily accessible, low-waste sensor that could simply be licked by patients to analyse their saliva.

They have turned to a surprising material, Tootsie Roll candy, to develop an inexpensive and low-waste device.

The candy was used as an electrode, the part of the sensor that detects salt and electrolyte levels in saliva, to monitor ovulation status or kidney health.

To make the prototype sensor, the researchers first flattened a Tootsie Roll and pressed crevices into its surface in a crosshatched pattern to hold the saliva sample. Then, they inserted two thin, reusable Aluminum tubes, which acted as electrical contacts, connecting the candy electrode into a circuit with a current source and an output voltage detector.

Ovulation predictor kits measure luteinizing hormone levels, and there are test strips that measure creatinine levels for patients with chronic kidney disease.

Researchers say that using soft candy as electrodes opens up the possibility for low-waste, inexpensive electrochemical sensors and circuits in the future.