Nanoparticles Make At-Home Stress Testing Possible

Researchers have developed a sensor using nanoparticles that can specifically detect cortisol levels, a key stress biomarker, with greater reliability than current methods. This affordable and easily replicable device moves us closer to being able to test stress levels at home.

Stress is a common challenge for many individuals. Whether triggered by work, personal situations, or financial concerns, stress causes your body to release a wave of cortisol after the initial ‘fight or flight’ response, keeping you on edge. It’s a well-known fact that stress negatively impacts health.

Advancing Stress Monitoring with a Cost-Effective Cortisol Detection Sensor

Since cortisol is a key biomarker for stress, sensors that can accurately measure its levels are crucial for monitoring stress and intervening when necessary. To address this need, researchers from Xi’an Jiaotong-Liverpool University (XJTLU) have developed a low-cost, accurate device for detecting cortisol using nanoparticles.

“A cost-effective, easily replicable, and user-friendly point-of-care testing device that can accurately measure cortisol levels is something we have been eager to develop,” said Tong Ji, the study’s lead author and a current PhD student and senior technician at XJTLU. “Such a device could greatly enhance the timely and accurate diagnosis of cortisol levels, significantly improving people’s lives.”

However, current cortisol detectors use silver electrodes, which can become unstable in extreme conditions with fluctuating temperatures and pH levels, resulting in a short lifespan and limited commercial viability.

“Existing cortisol detectors have reference electrodes with a silver layer that easily oxidizes, making them unstable in electrochemical measurements,” explained Ji. “In our study, we coated the silver layer with iridium oxide nanoparticles. This modification enhances the stability, sensitivity, and reproducibility of cortisol detection in point-of-care devices.”

Enhancing Point-of-Care Testing with Iridium Oxide Technology

Point-of-care testing refers to conducting the analysis close to the patient, such as at home, in a pharmacy, or at a medical clinic. The researchers discovered that electrodepositing iridium oxide (IrOx) on a gold electrode enables highly sensitive cortisol detection.

“This is the first time iridium oxide has been utilized in this manner,” stated Dr. Qiuchen Dong, an assistant professor at XJTLU and a co-corresponding author of the study. “Our team has developed a simple, low-cost device that can measure cortisol levels at concentrations 3,000 times lower than the normal range found in blood, making it sensitive enough for commercial applications.”

However, an additional advantage of the IrOx-coated sensor is its ability to differentiate cortisol from other similar hormones.

“One issue with current solutions is the significant similarity between cortisol and other hormones like progesterone, testosterone, and corticosterone,” explained Dr. Graham Dawson, a professor in the Department of Chemistry at XJTLU and a co-author of the study. “This similarity makes it challenging for detectors to distinguish between them. Our iridium oxide-modified electrode is selective enough to differentiate these hormones, effectively addressing this problem.”

This device brings us closer to enabling stress testing at home.

Read the original article on: New Atlas

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