Reagentless electrochemical biosensor based on the multi-wall carbon nanotubes and nanogold particles composite film

A novel method was used to prepare the nanocomposite by assembling nanogold (NG) particles on the multiwall carbon nanotubes (MWNTs) surface. The nanocomposite could be immobilized on a glassy carbon ( GC) electrode to get a novel modified electrode. The electrode can easily immobilize the horseradish peroxidase (HRP) molecules to construct a reagentless biosensor. The NG particles in the composite film have a good biological compatibility. And due to the existence of quinone groups on the MWNTs surface, the MWNTs can promote the electron transfer between enzymes and electrode surface. The biosensor shows a good stability and responds to H2O2 in the range from 2.0 mu M to 3.5 mM with a detection limit of 1.0 mu M.