Improved adhesion and performance of vertically-aligned mesoporous silica-nanochannel film on reduced graphene oxide for direct electrochemical analysis of human serum

Vertically-aligned mesoporous silica-nanochannel film (VMSF) has been demonstrated as effective anti-fouling and anti-inference layer for constructing electrochemical sensors. Conductive substrate with high electroactivity and adhesion is very important for improving the performance of VMSF based sensors in terms of stability, sensitivity and discrimination ability. We herein use reduced graphene oxide (rGO) sheets as conductive adhesive and electroactive layer between VMSF and glassy carbon electrode (GCE). VMSF can be stably grown on rGO layer by electrochemically assisted self-assembly method (EASA). Owing to the electroactive properties of rGO, VMSF/rGO/GCE is able to parallel or simultaneously detect small drugs or biomarkers with high sensitivity and distinct oxidation potential for different electroactive organic molecules. Combining the anti-fouling and anti-inference ability of VMSF, direct analysis of small drugs or biomarkers in complex biological (serum) sample is demonstrated.