Graphene Field-Effect Transistors with Surface-Charge Modulation for C-Reactive Protein Detection in Artificial Saliva

Saliva-based biosensors are emerging as viable tools for noninvasive, painless, and easily administered household medical diagnostics. Despite their potential, the complexity of saliva, containing various non-target molecules and contaminants, presents significant challenges due to nonspecific interactions with biosensors. This study utilizes surface-charge modulated graphene field-effect transistors (SCM-GFETs) for the detection of C-reactive protein (CRP) in artificial saliva, using portable measurement apparatus. Our findings indicate that SCM-GFETs exhibit nonspecific responses to saliva components. To address this issue, a two-step preprocessing method is implemented: diluting the saliva in phosphate-buffered saline at a 1 : 104 ratio and subsequent membrane filtration. This process significantly reduced nonspecific interactions, enabling CRP detection in saliva samples. These advancements hold promise for enhancing graphene field-effect transistor technology in point -of -care diagnostic devices.