Electrochemical impedance spectroscopy study on polymerization of L-lysine on electrode surface and its application for immobilization and detection of suspension cells.

Poly-L-lysine (PLL), which has been employed as a conductive polymer in the construction of some electrochemical sensors, can be prepared using L-lysine by cyclic voltammetry (CV) with a wide potential range. However, the presented explanation and description about its polymerization mechanism seems oversimplified because the self-reaction of electrode and the electrolysis of solvent at high potential are ignored. This work presents an intensive investigation on the relevant reactions during the process of PLL-polymerization using CV, X-ray photoelectron spectroscopy, Fourier transform-infrared spectroscopy, and electrochemical impedance spectroscopy.

Electrochemical immunoassay for carcinoembryonic antigen using gold nanoparticle-graphene composite modified glassy carbon electrode.

Carcinoembryonic antigen (CEA), which is typically associated with certain tumors and developing fetus, is widely used as a clinical tumor marker for some familiar cancers. In this work, a simple and sensitive electrochemical CEA sensor was developed by employing immunoreaction. Gold nanoparticle-decorated graphene composites (Au-GN) were successfully synthesized based on the reduction of HAuCl4 in the presence of graphene.