Glucose oxidase immobilization platform based on ZnO nanowires supported by silicon nanowires for glucose biosensing

• This research provides a meaning way for integratable glucose sensors.
• High specific surface area, numerous microspaces, and small channels for fluid circulation provided by this unique structure
• Good biocompatibility and high isoelectric point (IEP) fractures of ZnO make the product an ideal platform for the immobilization of enzymes.
• Short transport/diffusion path lengths, timely accompanying of electrolyte result high sensitivity

A nanostructured platform composed of ZnO nanowires supported by silicon nanowires (ZnO/SiNWs) is utilized to immobilize glucose oxidase on a glucose enzymatic biosensor. The SiNWs arrays are fabricated by a simple metal-catalyzed solution method under normal conditions and ZnO nanowires about 650 nm long are produced on the wall of the silicon nanowires by aqueous thermal decomposition. The large specific surface area, abundant microspace, small channels, and high isoelectric point (IEP) fracture of ZnO enable effective fluid circulation and good biocompatibility boding well for immobilization of enzymes. The nanocomposite materials show good electrocatalytic activity exhibiting strong and sensitive response to glucose even in the presence of high concentrations of interfering species besides excellent long-term stability and reproducibility.

The SiNWs exhibit a bundle-like structure and are vertically aligned to the substrate. The length of the SiNWs is uniform and about 90 μm and the diameter ranges from 60 to 300 nm. The ZnO nanowires on the SiNWs also have a bundle-like structure and many ZnO nanowires are formed on the vertically aligned SiNWs. The length of the ZnO is also uniform and about 650 nm and the diameter is approximately 100–150 nm which depends on the fabrication time.A good linear relationship is found between the catalytic current and glucose concentration. The sensitivity calculated from the calibration curve is 129 μA mM− 1.Figure optionsDownload as PowerPoint slide