Innovative Bio(Nano)Sensor Designs for Cortisol Stress Hormone Detection: A Continuous Progress

Nowadays, the population is subject to a lot of stress, being one of society’s most encountered problems affecting people all over the world. Being under a lot of stress for prolonged periods of time impacts the physical and mental health of individuals with effects on society as an economic burden. Cortisol is one of the main indicators of stress. Long-term exposure to this stress hormone can lead to severe medical conditions such as heart disease, lung issues, obesity, anxiety, or depression. In this context, the current review aims to provide a comprehensive overview of the most recent advances made in the development of versatile and efficient cortisol devices and biosensors capable of monitoring the cortisol levels in biofluids. Lately, both non-plasmonic (polymer-based sensors, optical sensors, electrochemical sensors) and plasmonic sensors (mono- and multiple-metallic nanoparticles-based sensors) have shown great results in cortisol detection. The work focuses on the advantages, remaining restrictions, and limitations in the field of cortisol biosensors from solution-based immunosensors to wearable and Lab-on-Skin monitoring devices, providing a better understanding of the fulfilled requirements and persisting challenges in the accurate detection and monitoring of the cortisol stress hormone.