Study on Electrochemical Biosensor Based on Alumina Nanochannels

The perfectly ordered alumina nanochannels prepared by binary anodic oxidation was modified with amino-groups on the surface by reacting with 3-aminopropylethoxysilane and then reacted for 12 h in a buffer solution (pH 5.5) containing biotin to immobilize biotin on the surface of the nanochannels with bore diameters of ca. 50 nm. Circular slice of polymer membrane with  7 mm was glued with PVC/THF solution on the top of a length of PVC tubing, and the modified alumina nanochannels prepared was glued on the base of the membrane with organic silicone rubber, which was to be used as working electrode. Potentiometric study was made with biotin-avidin system as a mode, using the modified alumina nano-channels as discerning carrier. Linear relationship between values of potential change and mass concentration of avidin was kept in the range of 0.10 to 0.60 mg·L-1, with detection limit (3σ) of 0.05 mg·L-1. Feasibility of determination of bio-materials of macro-molecules using the modified alumina nanochannels as bio-sensor in potentiometry was proved.