Emerging trends in wearable and non-invasive cortisol sensing technologies - a review

Emerging wearable cortisol sensors represent a significant innovation in personalized health monitoring, allowing for detection of cortisol, a key biomarker for stress, chronic diseases, and overall well-being. Since cortisol regulates stress and metabolic functions, monitoring its levels can aid in early disease detection and enhance health management. These sensors incorporate advanced technologies such as electrochemical sensors with molecularly imprinted polymers, immunosensors, and aptamer-based sensors, ensuring high sensitivity and accuracy. Optical sensors and FETs, using nanostructures and flexible substrates, improve detection precision and enable seamless integration into wearable devices. Recent advancements in fabrication techniques, including microfluidics, roll-to-roll printing, and nanofabrication, have made large-scale production of these sensors feasible and cost-effective, without sacrificing comfort or adaptability. Key features include reliable power sources and wireless communication for continuous data transmission. Additionally, machine learning algorithms and computational models enable in-depth analysis of cortisol fluctuations, offering valuable insights into their health implications. Applications for these sensors range from stress management and chronic disease monitoring to sports performance and personalized healthcare. Future advancements are expected to emphasize sensor miniaturization, integration with artificial intelligence, and the development of multi-modal sensing platforms, thereby enhancing the potential of wearable cortisol sensors to revolutionize healthcare through personalized, proactive, and preventive strategies.