Nonenzymatic glucose sensor based on over-oxidized polypyrrole modified Pd/Si microchannel plate electrode.

A silicon microchannel plate (MCP) array electrode modified with over-oxidized polypyrrole (OPPy) has been fabricated to detect glucose. The morphology and structure of the electrode are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The OPPy modified silicon MCP array electrode exhibits high electrocatalytic activity as well as excellent selectivity to the electrochemical oxidation of glucose. At a potential of +0.08 V, good sensitivity of 0.37 mA mM(-1) cm(-2) and detection limit of 2.06 µM are attained. The linear range is up to 24 mM with a linear correlation coefficient of 0.997. Furthermore, the electrode is highly resistant to interfering substances because the effects of common coexisting substances can be effectively eliminated by the OPPy film and the response in the current to interferences on the electrode surface is almost negligible. This novel electrode has high potential in nonenzymatic detection of glucose.

Investigation of inner surface of silicon microchannels fabricated by electrochemical method.

Various silicon-based microchannels with different internal surface morphologies were investigated to improve the growth of carbon nanotubes on the inner surface of the pore wall. The morphology of the samples prepared under different conditions was characterized by scanning electron microscopy. Parameters such as concentration of hydrofluoric acid, potential, current density, temperature and so on were found to affect the inner surface of the pore wall. Experiments showed that certain etchant concentration, current density and temperature were important to the fabrication of samples with the regular structure and good morphology. By considering these factors, samples with the proper internal pore surface could be fabricated. Nickel was adopted as the metallic catalyst during electroless deposition onto the surface of the pore wall and bottom. The nickel/silicon microchannels were characterized and found to be suitable for the fabrication of carbon nanotubes by thermal chemical vapor deposition.