New Dental Floss Sensor Tracks Stress Hormone Cortisol in Real Time: Study Shows - Video

A team led by Tufts University engineer Sameer Sonkusale has developed an innovative, real-time stress monitoring device that uses a simple floss pick to detect cortisol levels in saliva. The research, published in ACS Applied Materials and Interfaces, offers a low-cost, non-invasive, and highly accurate alternative to traditional stress assessment tools, which often rely on subjective self-reporting or expensive medical evaluations.

Their design of a saliva-sensing dental floss looks just like a common floss pick, with the string stretched across two prongs extending from a flat plastic handle, all about the size of your index finger. The saliva is picked up by capillary action through a very narrow channel in the floss. The fluid is drawn into the pick handle and an attached tab, where it spreads across electrodes that detect the cortisol.

Cortisol recognition on the electrodes is accomplished with a remarkable technology developed almost 30 years ago called electropolymerized molecularly imprinted polymers (eMIPs). They work similarly to the way you might make a plaster cast of your hand. A polymer is formed around a template molecule, in this case cortisol, which is later removed to leave behind binding sites. These sites have a physical and chemical shape "memory" of the target molecule so they can bind free-floating molecules that are coming in.

"The eMIP approach is a game changer," said Sonkusale, professor of electrical and computer engineering. Unlike traditional biosensors that rely on engineered antibodies or receptors, eMIPs enable faster and more flexible sensor development. The technology can also be adapted to detect other biomarkers in saliva, including estrogen, glucose, or cancer indicators.

Sonkusale emphasized that while blood remains the "gold standard" for diagnosis, saliva-based monitoring provides an easy, non-invasive way to track health changes over time. “If you need to track, say, a cardiovascular condition over time to see if your heart health is improving, then monitoring with the sensor can be easy and allows for timely interventions when needed.”

Reference: Atul Sharma, Nafize Ishtiaque Hossain, Ayanna Thomas, Sameer Sonkusale. Saliva-Sensing Dental Floss: An Innovative Tool for Assessing Stress via On-Demand Salivary Cortisol Measurement with Molecularly Imprinted Polymer and Thread Microfluidics Integration. ACS Applied Materials & Interfaces, 2025; 17 (17): 25083 DOI: 10.1021/acsami.5c02988