A Facile Electrochemical Immunosensor with Mesoporous Alumina for Detection of Carcinoembryonic Antigen

Abstract

Abstract A label‐free electrochemical immunosensor for the sensitive determination of carcinoembryonic antigen (CEA) was fabricated by immobilizing anti‐CEA onto mesoporous alumina ( meso ‐Al 2 O 3 ) dispersed in chitosan (0.5 %wt) by the cross‐linking method using glutaraldehyde. Due to its plenty of active sites, meso ‐Al 2 O 3 showed high catalysis towards hydroquinone. With the electrocatalytic ability of meso ‐Al 2 O 3 for the reduction of hydroquinone, the current signal of the antigen‐antibody reaction was amplified and the enhanced sensitivity was achieved. The current decreased linearly with CEA concentration in the range of 0.04 to 10 ng/mL (26 pg/mL, S / N =3). The immunosensor had good selectivity and wonderful stability. Furthermore it was applied to the analysis of CEA in serum sample with satisfactory results.