Researchers at Rutgers University have developed a microchip that can perform real-time measurements of stress hormone levels in a drop of blood. The technology could provide a replacement for bulky and expensive lab tests for such hormones, and allow patients to monitor their stress levels more easily. The chip includes tiny wells that contain antibodies, and the technology monitors antibody binding through impedance measurements performed using electrodes within the device.
Life has been stressful for many people during the pandemic, where illness, lockdowns and general societal turmoil have contributed to mental health issues and chronic stress. Aside from being an unpleasant experience, chronic stress is bad news for our health. Stress can be a big factor in sleep impairment, cardiac issues, and panic attacks, among other conditions.
One of the most effective ways to measure stress levels and provide concrete data on whether interventions are helping to reduce stress involves measuring levels of the stress hormone cortisol in blood. However, this is not convenient at present, as it requires a lab test, using techniques such as ELISA (enzyme-linked immunosorbent assay), which do not easily allow for point-of-care readings and require bulky equipment and highly trained laboratory technicians.
This latest technology aims to help patients measure the natural changes in cortisol levels and monitor trends over time, without having to send blood samples to a lab. “The use of nanosensors allowed us to detect cortisol molecules directly without the need for any other molecules or particles to act as labels,” said Reza Mahmoodi, a researcher involved in the study, via a Rutgers press release.
The new chip was fabricated on a glass substrate and contains an array of tiny wells and electrodes. The electrodes can measure antibody binding within the device to provide sensitive measurements of cortisol levels in blood samples. So far, the researchers tested the device with human blood samples and showed that it is comparable in its accuracy and sensitivity to ELISA.
“With technologies like the new microchip, patients can monitor their hormone levels and better manage chronic inflammation, stress and other conditions at a lower cost,” added Mehdi Javanmard, another researcher involved in the study. “Our new sensor produces an accurate and reliable response that allows a continuous readout of cortisol levels for real-time analysis. It has great potential to be adapted to non-invasive cortisol measurement in other fluids such as saliva and urine. The fact that molecular labels are not required eliminates the need for large bulky instruments like optical microscopes and plate readers, making the readout instrumentation something you can measure ultimately in a small pocket-sized box or even fit onto a wristband one day.”
Study in Science Advances: Single-step label-free nanowell immunoassay accurately quantifies serum stress hormones within minutes