Detection of six glucocorticoids using a nanogold-glucocorticoid receptor-based biosensor

This study introduces a novel biosensor based on a glassy carbon electrode (GCE) modified with nanogold and glucocorticoid receptors (GR) for the sensitive and selective detection of glucocorticoids. The biosensor employs a sensing methodology that capitalizes on the specific adsorption of glucocorticoid molecules to the GR-modified electrode surface, forming a sandwich complex structure that impedes electron transfer, detectable by differential pulse voltammetry (DPV). Electrochemical characterization through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated enhanced electron transfer rates and the effects of electrode surface modifications on the biosensor’s performance. Optimization studies identified ideal conditions for GR concentration and incubation time, enhancing the biosensor’s immune response and detection efficiency. The biosensor exhibited outstanding detection capabilities for six glucocorticoids, with a detection limit ranging from 0.012 to 0.065 ng⋅mL −1 and a broad linear range of 0.1 to 1000 ng⋅mL −1 . Its performance surpassed conventional detection methods, attributing to the conductivity and nanoscale effects of nanogold. Repeatability and stability assessments confirmed the biosensor’s reliability and potential for practical applications. Analysis of actual skincare samples further validated the biosensor’s effectiveness in real-world scenarios, demonstrating high accuracy and recovery rates. The study underscores the biosensor’s potential as a robust tool for environmental analysis, food safety, clinical diagnosis, and on-site glucocorticoid detection, offering significant advantages in terms of cost-effectiveness, portability, and response time.