J0201-3-1 Cortisol Sensor Used for Diagnosis of Stress-related Diseases

Abstract

As a key biomarker of the individual stress response, cortisol is the increasing focus of psychobiological stress research. The ability to provide real-time scan of cortisol levels will open up substantial new possibilities. We describe an immuno-chromatographic technique allows point-of-use measurement of cortisol (CORT) manifesting in readily accessible human saliva. A disposable test-strip serves as the biosensing platform for salivary CORT. In order to realize the test-strip, we synthesized a glucose oxidase (GOD)-CORT conjugate. Introducing a saliva sample onto the collection pad produces a red band after 20 minutes. The reflectance of the band is measured by an optical analyzer and the CORT concentration calculated by using a calibration curve (R^2 = 0.945). The sensitivity of our test-strip (1 ng/ml) is adequate to analyze human salivary CORT.