An electrochemical biosensor constructed by nanosized silver particles doped sol–gel film

The nanosized silver particles are used to dope into the sol–gel film to prepare a biosensor. The horseradish peroxidase (HRP), mediator methylene blue (MB), nanosized silver particles and sol–gel solution are mixed and coated on the surface of glass carbon (GC) electrode to get the biosensor. The silver nanoparticles in the sol–gel film can adsorb the enzyme molecules and improve the sol–gel film conductivity. The biosensor has a high sensitivity, quickly response to H2O2 and good stability. The biosensor responds to H2O2 in the linear range from 1 μM to 1 mM. The detection limit was down to 0.4 μM when the signal to noise ratio is 3. The apparent Michaelis-Menten constant of the biosensor to H2O2 was estimated to be 1.2 mM, showing a high affinity.