Innovative Artificial Protein Sensor Revolutionizes Cortisol Measurement via Smartphone

In a groundbreaking development in the field of medical diagnostics, researchers at the University of California, Santa Cruz, have unveiled an artificial protein sensor that allows individuals to measure cortisol levels using a smartphone. This significant innovation, led by Dr. Andy Yeh, Assistant Professor of Biomolecular Engineering, represents a major advancement in point-of-care testing and could transform the way cortisol — a hormone crucial for regulating various bodily functions such as blood pressure and metabolism — is monitored. The study detailing this advancement was published in the Journal of the American Chemical Society on July 29, 2025.

Cortisol, often referred to as the stress hormone, plays a vital role in the body's response to stress. Imbalances in cortisol levels can lead to a variety of health issues, including anxiety, depression, and metabolic disorders. Traditionally, cortisol testing requires clinical intervention, limiting accessibility and timely diagnosis for patients.

Dr. Yeh's innovative sensor employs artificial luminescence to detect cortisol in blood or urine samples. The sensor comprises two designed proteins that, when cortisol is present, come into close proximity, resulting in light emission. This light can then be captured and analyzed using a smartphone camera, providing immediate and accurate results. Dr. Yeh stated, "You can read the signal directly — the output of the sensor is light emissions, so essentially you can just take a picture of the test with your smartphone. Ideally, that’s really field compatible."

This new testing method signifies a leap forward from existing cortisol assays, which often fail to provide quantitative results when cortisol levels are not within the normal range. Yeh emphasized that the new sensor offers a broader dynamic range, allowing for precise measurements across healthy, low, and elevated cortisol levels. The sensor's design was based on AI-guided computation, marking it as the first instance of a computationally designed biosensor demonstrating such high sensitivity and dynamic range.

The research was supported by the National Institutes of Health's National Institute of Biomedical Imaging and Bioengineering, the Chan Zuckerberg Initiative, and the UC Santa Cruz start-up fund. The potential applications of this technology extend beyond individual health monitoring; it could also aid in drug development and diagnostics for conditions arising from cortisol imbalances.

Dr. Yeh envisions that the sensor could eventually be used to better understand and treat health issues related to cortisol deficiencies or surpluses. As the technology evolves, it promises to enhance patient engagement in their health management and reduce the reliance on clinical settings for routine hormone monitoring.

In summary, the advent of this artificial protein sensor not only democratizes access to cortisol testing but also exemplifies the growing intersection of biotechnology and mobile technology. As healthcare becomes increasingly personalized, innovations like these may pave the way for more responsive and accessible healthcare solutions, highlighting the importance of continued investment in research and development in the life sciences sector.