Real-time reliable detection of adrenocorticotropic hormone using reduced graphene oxide field-effect transistors†

Abstract

Adrenocorticotropic hormone (ACTH), a pivotal regulator in stress response and cortisol production, poses substantial detection challenges owing to its low plasma concentration, susceptibility to fluctuations, and storage-related stability issues. We developed an innovative nano-immunobiosensor platform to overcome these limitations that integrates reduced graphene oxide (RGO) with field-effect transistor (FET) technology. This platform employs anti-ACTH-directed detection to achieve rapid, sensitive, and real-time quantification of ACTH levels. The RGO-FET design capitalizes on the binding capacity of ACTH to pre-arrange anti-ACTH, thereby enhancing target engagement and enabling swift recognition of unlabeled ACTH. The sensor exhibits remarkable sensitivity, detecting ACTH concentrations as low as 0.124 fM in PBS. Furthermore, Bland–Altman analysis comparing our method with existing techniques using clinical samples reveals a high degree of methodological agreement, with 96% of results falling within the 95% confidence interval, underscoring its excellent precision. The principal advantage of this nano-immunobiosensor is its capability for real-time ACTH detection in clinical samples, making it an up-and-coming candidate for a sensitive point-of-care (POCT) diagnostic solution.