Abstract

In this paper, carboxyl-ferrocene (Fc-COOH) was explored to label alphafetoprotein antibody (anti-AFP), which was then mixed with AU nanoparticles (nano-Au) and multi-walled carbon nanotubes (MWCNTs) dispersed by chitosan (CS) to form the nano-Au/MWCNTs/anti-AFP-Fc chitosan composite. After that, the composite was immobilized onto the surface of the electrode to prepare a reagentless amperometric alphafetoprotein (AFP) immunosensor. The experimental results indicated that, the proposed immunosensor had good current response to AFP with a linear range from 0.1 to 50 ng/ml with a detection limit of 0.03 ng/ml. Moreover, the electrochemical properties and performance were investigated by the cyclic voltammetry. The results also found that, the immunosensor owned the advantages of high stability, simple preparation and operation and well regeneration performance.

Key words: Multi-walled carbon nanotubes (MWCNTs), Au nanoparticles (nano-Au), chitosan (CS), amperometric immunosensor, alphafetoprotein (AFP).

Abbreviation

AFP, Alphafetoprotein; anti-AFP, alphafetoprotein antibody; Fc-COOH, carboxyl-ferrocene; MWCNTs, multi-walled carbon nanotubes; nano-Au, Au nanoparticles; CS, chitosan; ELISA, enzyme-linked immunosorbent assay;IRMA, immunoradiometric assay; EDC, N-(3-dimethylaminopropyl)-N¢-ethylcarbodiimidehydrochloride; NHS, N-hydroxy succinimide; BSA, bovine serum albumin; PBS, phosphate buffered solution; CVD, chemical vapor deposition; SCE,saturated calomel reference electrode.