Could a simple dental hygiene routine unlock insights into your stress levels? Researchers have developed a novel saliva-sensing dental floss capable of real-time cortisol detection, offering a convenient and non-invasive method for stress monitoring [1] [3]. This innovative approach utilizes advanced polymer technology to measure cortisol, a key stress hormone, directly from saliva and may pave the way for at-home monitoring of various health conditions [2].
Summary: Engineers have developed a novel dental floss device that can detect cortisol, a hormone linked to stress, through saliva, offering a painless, real-time method for stress monitoring. The device uses electropolymerized molecularly imprinted polymers (eMIPs), which act like custom molds to recognize specific molecules.
With accuracy comparable to current biosensors, this floss-based tech could make stress tracking part of daily routines. Researchers aim to adapt the system for other saliva-based health markers, potentially transforming personal health monitoring across conditions.
Key Facts:
- Stress Detection: The floss-based sensor measures cortisol from saliva using advanced polymer molds.
- Multi-Marker Potential: Can be adapted to detect other biomarkers, like glucose or estrogen.
- Home Use: Designed for untrained individuals, making daily stress tracking simple and noninvasive.
Source: Tufts University
Chronic stress can lead to increased blood pressure and cardiovascular disease, decreased immune function, depression, and anxiety.
Unfortunately, the tools we use to monitor stress are often imprecise or expensive, relying on self-reporting questionnaires and psychiatric evaluations.
Now a Tufts interdisciplinary engineer and his team have devised a simple device using specially designed floss that can easily and accurately measure cortisol, a stress hormone, in real time.
“It started in a collaboration with several departments across Tufts, examining how stress and other cognitive states affect problem solving and learning,” said Sameer Sonkusale, professor of electrical and computer engineering.
“We didn’t want measurement to create an additional source of stress, so we thought, can we make a sensing device that becomes part of your day-to-day routine?
“Cortisol is a stress marker found in saliva, so flossing seemed like a natural fit to take a daily sample.”
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 molds are versatile, so one can create dental floss sensors that detect other molecules that can be found in saliva, such as estrogen for fertility tracking, glucose for diabetes monitoring, or markers for cancer.
There is also potential for detecting multiple biomarkers in saliva at the same time, for more accurate monitoring of stress, cardiovascular disease, cancer, and other conditions.
“The eMIP approach is a game changer,” said Sonkusale.
“Biosensors have typically been developed using antibodies or other receptors that pick up the molecule of interest. Once a marker is found, a lot of work has to go into bioengineering the receiving molecule attached to the sensor. eMIP does not rely on a lot of investment in making antibodies or receptors.
“If you discover a new marker for stress or any other disease or condition, you can just create a polymer cast in a very short period of time.”
Accuracy of the cortisol sensors is comparable to the best-performing sensors on the market or in development. Bringing this device into the home and in the hands of individuals without need for training will make it possible to fold stress monitoring into many aspects of health care.
Currently Sonkusale and his colleagues are creating a startup to try and bring the product to market.
He points out that while the dental floss sensor is quantitatively highly accurate, the practice of tracking markers in saliva is best for monitoring, not for the initial diagnosis of a condition. That’s in part because saliva markers can still have variations between individuals.
“For diagnostics, blood is still the gold standard, but once you are diagnosed and put on medication, 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,” he says.
The new research, published in the journal ACS Applied Materials and Interfaces, adds to a number of thread-based sensor innovations by Sonkusale and his research team including sensors that can detect gases, metabolites in sweat, or movement when embedded in clothing and transistors that can be woven into flexible electronic devices.
About this mental health and neurotech research news
Author: Mike Silver
Source: Tufts University
Contact: Mike Silver – Tufts University
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Saliva-Sensing Dental Floss: An Innovative Tool for Assessing Stress via On-Demand Salivary Cortisol Measurement with Molecularly Imprinted Polymer and Thread Microfluidics Integration” by Sameer Sonkusale et al. ACS Applied Materials and Interfaces
Abstract
Saliva-Sensing Dental Floss: An Innovative Tool for Assessing Stress via On-Demand Salivary Cortisol Measurement with Molecularly Imprinted Polymer and Thread Microfluidics Integration
On-demand dental-floss-based point-of-care platform is developed for the noninvasive and real-time quantification of salivary cortisol utilizing redox-molecule embedded molecularly imprinted polymer structures and thread microfluidics.
Herein, we explore the high-surface-area graphene-based electrode substrate for electrochemically synthesizing selective cortisol MIPs and integrate it with thread microfluidics to build a highly sensitive cortisol-sensing platform for stress monitoring.
This platform uses flossing to collect and transport saliva to a flexible electrochemical sensor via capillary microfluidics, where cortisol, a stress biomarker, is measured. This strategy allowed us to detect cortisol as low as 0.048 pg mL–1 in real-time with a detection range of 0.10–10,000 pg mL–1 (R2 = 0.9916).
The saliva-sensing dental floss provides results within 11–12 min. The thread-based microfluidic design minimizes interference and ensures consistent repeatability when testing both artificial and actual human saliva samples, yielding 98.64–102.4% recoveries with a relative standard deviation of 5.01%, demonstrating high accuracy and precision.
For the human saliva sample (as part of the stress study), the platform showed a high correlation (r = 0.9910) against conventional ELISA assays.
Combined with a wireless readout, this saliva floss offers a convenient way to monitor daily stress levels. It can be extended to detect other critical salivary biomarkers with high sensitivity and selectivity in complex environments.
