Fast one-step fabrication of a vertically-ordered mesoporous silica-nanochannel film on graphene for direct and sensitive detection of doxorubicin in human whole blood

Developing ordered mesoporous silica-based membranes with highly sensitive detection performance is of great significance for direct electrochemical detection in biological fluids against surface biofouling. Herein, we describe a facile one-step approach for the integration of a vertically-ordered mesoporous silica-nanochannel film (VMSF) with electrochemically reduced graphene oxide (ErGO) by an electrochemically assisted self-assembly (EASA) method. Electrochemical reduction of GO and growth of the VMSF simultaneously occur in a simple one-step process, forming a VMSF/ErGO layer on the glassy carbon electrode (GCE). Arising from the oxygen-containing groups, hydrophobic pi-conjugated structure, and the two-dimensional planar structure of ErGO, the VMSF could be stably grown on the GCE surface and it further acted as a protective layer to prevent the internal ErGO electroactive layer from falling off the electrode surface over prolonged use. In comparison with a bare GCE, the present VMSF/ErGO/GCE sensor exhibits an excellent response to doxorubicin with a wide linear range (1 nM-20 mu M), a high sensitivity (7.815 mu A mu M-1) and a low limit of detection (0.77 nM), due to the cooperative signal amplification originating from the electrocatalytic activity and pi-pi interaction of ErGO and electrostatic preconcentration effect of the VMSF. Furthermore, considering the outstanding anti-fouling and anti-interference ability of the VMSF, direct determination and long-term monitoring of doxorubicin in human whole blood was successfully achieved by the sensor.