June 2021
Vol 7, Issue 27

About The Cover

Cover image expansion

ONLINE COVER The ability to measure cortisol levels as an indicator of stress has gained attention for personalized health monitoring, since cortisol dysregulation may accompany sleep disorders. Real-time continuous monitoring of cortisol levels is most useful, but conventional cortisol detection approaches, such as the standard enzyme-linked immunosorbent assay (ELISA), must be performed in a laboratory setting and involve expensive diagnostic tools. To overcome this challenge, Mahmoodi et al. developed a single-step immunoassay using a novel nanowell array design that integrates two probe electrodes within the nanowell structure. The platform consists of a 28-well plate biochip built on a glass substrate and can detect cortisol concentrations between 1 and 15 micrograms per decilitre in buffer solution. Mahmoodi and colleagues compared the novel platform's measurements of 65 human serum samples with results from ELISA, confirming that nanowell array sensors could provide real-time, lab-quality diagnostic results for point-of-care testing. [CREDIT: ELLA MARUSHCHENKO]