Controllable interfacial coupling of graphene in papermaking process for selective bio-detection with high sensitivity

Abstract

Carbon paper-based electrochemical sensors offer the possibility of long-term in vivo monitoring of the biomarkers due to their chemical stability and porous structure. However, the serious self-staking and aggregation of the carbon materials seriously block the diffusion of target biomolecules and limit the sensitivity and selectivity of the device. Here we report a controllable interfacial coupling strategy in which a composite paper electrode made by electrostatic self-assembling reduced graphene oxide (rGO) on carbon fiber (CF) modified with cationic polyacrylamide to avoid the self-stacking in scalable wet papermaking and thus increased accessible electrochemically active surface area and accelerate the diffusion of biomarkers. The resulting composite paper shows improved stability, high selectivity, long-durability, and excellent sensitivity in the electrochemical detection of biomarkers such as ascorbic acid, dopamine, and uric acid. Our approach, which combines mature industrial paper technology with interface engineering and electrochemical reduction, offers a potential avenue for low-cost and scalable implantable electrodes for timely and long-term monitoring in the surgical and clinical applications.