A simple electrochemical immunosensor based on worm-like platinum for highly sensitive determination of alpha-fetoprotein.

Alpha-fetoprotein (AFP) has become a specific tumor marker of primary liver cancer in clinical diagnosis. In this work, we prepared worm-like platinum (WL Pt) nanomaterial via chemical etching without organic solvents and ultra-high temperature. Due to its small particle size and the formation of surface vacancies during the etching process, it had a large specific surface area, and thus exhibited superior electrocatalytic activity for the reduction of hydrogen peroxide. Combining the signal amplification based on hydrogen peroxide reduction and the specific recognition of antigen with antibody, we constructed a simple label-free electrochemical immunosensor with a sandwich-like structure. The developed electrochemical immunosensor showed a wide linear range (0.0001-100 ng mL), a low detection limit (0.028 pg mL), good selectivity and stability. Further, the immunosensor was comparable with enzyme-linked immunosorbent assay (ELISA) and had a good accuracy for AFP detection in human serum samples proving the feasibility of potential application, which is expect to become one of the most promising method in early diagnosis and clinical analysis for liver cancer.