At-home stress testing possible, thanks to nanoparticles

Stress is a bugbear for many people. Whether caused by work, life circumstances, or finances, when stressed, your body releases a surge of cortisol after its ‘fight or flight’ hormones, keeping you on high alert. It’s trite to say that stress contributes to poor health.

As cortisol is a well-known stress biomarker, sensors that accurately measure its levels are important for keeping tabs on stress and intervening when necessary. To that end, researchers from Xi’an Jiaotong-Liverpool University (XJTLU) have used nanoparticles to create a cortisol-detecting device that’s cheap and accurate.

“A cost-effective, easily reproducible, and easy-to-use point-of-care testing device that accurately measures cortisol levels has long been sought,” said Tong Ji, a current PhD student and senior technician at XJTLU and the study’s lead author. “It could make a huge difference to an appropriate and speedy diagnosis of cortisol levels, drastically improving people’s lives.”

“Current cortisol detectors have reference electrodes with a silver layer that is easily oxidized and unstable in electrochemical measurements,” Ji said. “In this study, we used iridium oxide nanoparticles to cover the silver layer. This modification improves the stability, sensitivity and reproducibility of cortisol detection in point-of-care devices.”

Image source: Ji et al. (2024), Talanta.