摘要
This article reports on carbon nanotube/manganese dioxide (CNT-MnO 2 ) composites as electrochemical tags for non-enzymatic signal amplification in immunosensing. The synthesized CNT-MnO 2 composites showed good electrochemical activity, electrical conductivity and stability. The electrochemical signal of CNT-MnO 2 composites coated glassy carbon electrode (GCE) increased by nearly two orders of magnitude compared to bare GCE in hydrogen peroxide (H 2 O 2 ) environment. CNT-MnO 2 composite was subsequently validated as electrochemical tags for sensitive detection of α-fetoprotein (AFP), a tumor marker for diagnosing hepatocellular carcinoma. The electrochemical immunosensor demonstrated a linear response on a log-scale for AFP concentrations ranging from 0.2 to 100ngmL -1 . The limit of detection (LOD) was estimated to be 40pgmL -1 (S/N=3) in PBS buffer. Further measurements using AFP spiked plasma samples revealed the applicability of fabricated CNT-MnO 2 composites for clinical and diagnostic applications.