Measurement of cortisol is a reliable approach to diagnosing psychological stress, as well as chronic diseases related to cortisol disorders. The hormone cortisol is released in the body during stressed and agitated status and has a high correlation with post-traumatic stress disorders and other related psychological diseases. Salivary cortisol level is an excellent index of the unbound plasma free cortisol. Cortisol level typically fluctuates throughout the day, and diagnosis of cortisol-related diseases and assessment of psychological stress level cannot rely on a single measurement; mapping cortisol levels over time through is necessary to identify trends indicative of psychological stress onset or diagnosis of disease. Current cortisol measurement techniques are lab-based and episodic, and cannot be used for continuous monitoring. We propose to create a wearable, in- mouth sensor that supports ambulatory monitoring of salivary cortisol in real time. The device leverages a new biosensor architecture consisting of a bioresponsive hydrogel and embedded conductive nanowire networks. The proposed biosensor is expected to achieve a detection limit of 0.2 nM with a response time of less than 5 minutes, as required for real-time detection applications. The proposed strategy enables sensitive, specific, and reversible detection of neutrally-charged cortisol without the addition of chemical reporters or redox reagents for signal transduction. Such capability overcomes the limits encountered in charge-based transistor/nanowire biosensors or electrochemical techniques. Integration with a custom amperometric read-out integrated circuit (IC) will provide high-resolution, quantitative sensor measurement in a mm-scale microchip and the addition of a Bluetooth low energy (BLE) wireless transceiver will provide real-time data transmission to a smartphone for processing, archiving, and upload to the cloud.

Public Health Relevance

Measurement of cortisol is a reliable approach to diagnosing psychological stress, as well as chronic diseases related to cortisol disorders, but current cortisol measurement techniques cannot be used for continuous monitoring. We propose to create a wearable, in-mouth sensor that supports ambulatory monitoring of salivary cortisol in real time. The device leverages a new hydrogel biosensor architecture, and it will additionally integrate wireless electronics in the mouth-worn device to allow dynamic cortisol level measurement with real-time data transmission to a smartphone for processing, archiving, and upload to the cloud.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21DE027170-02
Application #
9544149
Study Section
Special Emphasis Panel (ZDE1)
Program Officer
Lopez, Orlando
Project Start
2017-08-14
Project End
2019-07-31
Budget Start
2018-08-01
Budget End
2019-07-31
Support Year
2
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Oregon State University
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
053599908
City
Corvallis
State
OR
Country
United States
Zip Code
97331