Physical Vapor Deposited Zinc Oxide (ZnO) Nanoparticles For Reactive Oxygen Species (ROS) Biosensors

A nanoporous ZnO film was prepared by physical vapor deposited method and characterized by SEM,XRD,UV-Vis,electrochemical method etc..The SEM imagines shows ZnO particles with the diameter ranging from 50 to 100 nm are mostly aggregated into larger particles to form porous ZnO film.The XRD spectrum indicates that this film has a polycrystalline hexagonal wurtzite structure,And in the UV-Vis spectrum ZnO film shows an absorbance peak(368 nm)which corresponds to the bulk value of the band gap(3.37 eV).The electrochemical behaviors of Cyt.c and SOD that based on the ZnO film were studied.A direct electron transfer can be observed of Cyt.c and SOD.By electrochemical method we can confirm that Cyt.c and SOD are im mol/Lobilized stably in the nanoporous material.Spectrum studies indicated that Cyt.c and SOD were im mol/Lobilized in the ZnO film and kept activity.For these basis,we construct H₂O₂ biosensor and O₂^- biosensor.The O₂^-biosensor shows more remarkable analytical properties such as wider dynamical linear range(anodic current response:2—84μM min^-1,cathodic current response: 0.4-180μM min^-1),longer stability,lower detection limit(anodic:0.4μM min^-1, cathodic:0.1μM min^-1),faster response time(～4 s)and better reproducibility.The excellent analytical performance,together with notable characteristics of the nanostructured ZnO film,such as facility of preparation and miniature, biocompatibility,eventually gave us strong basis for in vivo determination of O₂^-.