Sensitive Detection of Adrenaline using Electrochemically Surface-Treated rGO-AuNPs Electrode

Adrenaline is an important biomarker for human stress and is also used as a pharmaceutical component to treat severe asthma attacks and allergic reactions. It is critical to develop sensors to sensitively detect/determine adrenaline. Nanomaterial integrating reduced graphene oxide and gold nanoparticles (rGO-AuNPs) is one of the important electrochemical sensing materials and is particularly attractive to microfluidics-based sensors, wearable sensors, disposable sensors, array sensors, and so on due to its ease and simplicity of fabrication. However, carbon materials (GO or rGO) usually have many functional groups or contaminants on their surface from their manufacture or preparation, which could be involved in electrochemical redox reactions to produce significant noise/background and thus deteriorate sensing performance. In this work, we developed a surface treatment approach using DC potential amperometry to minimize the background drift. Using the surface-treated electrodes, we further investigated and optimized electrode parameters for adrenaline detection. The experimental results showed that the rGO-AuNPs electrode exhibits a limit of detection (LOD) of 0.45 µM in buffer-based samples. The developed electrode is better than many reported electrodes for adrenaline detection in buffers in achieving a lower LOD. The results of this study would facilitate the use of rGO-AuNPs for adrenaline detection in wearable, disposable, portable, or on-chip sensing applications.