A homogeneous dispersion of multiwall carbon nanotubes(MWNT) was achieved by dispersing MWNT into 0.1% Nafion ethanol solution, and a uniform cast film at a glassy carbon electrode(GCE) was obtained via solvent evaporation of the MWNT dispersion. A reversible two-electron redox reaction of dopamine was observed at the MWNT-Nafion modified GCE. In comparison with a bare GCE and a Nafion-modified GCE, MWNT-Nafion modified GCE has a higher sensitivity for dopamine. This modified GCE has an excellent selectivity towards dopamine even in the presence of high concentration ascorbic acid(AA) and uric acid(UA) since AA and UA have no observable electrochemical responses at the modified GCE. The electrochemical behavior of dopamine was closely related to the pH of the buffer solution. The oxidation peak current was proportional to the concentration of dopamine over the range from 5×10 -8 to \{1×\}10 -6 mol/L, and a detection limit of 2.5×10 -9 mol/L was obtained after 3 min open-circuit accumulation. The dispersion and morphology of MWNT-Nafion film were investigated by transmission electron microscopy(TEM).
Five hybrid organic-inorganic mate rials have been prepared with pyrrole and the transition metal substitut ed Keggin structure phosphomolybdate anions(PMo 11ZO￡3￡1￡μ￡- ￡?Z ￡1/2Mn￡?Co￡?Ni￡?Cu￡?Zn￡(c)by chemical polymerization￡(r)The phosphomolybdates are anchored within the polymer matrix and reduced to mixedvalence phosphomolybdate s￡(r)The materials are characterized by e lemental analysis,IR spectra,thermogravimetric analysis,X-ray photoelectron spectroscopy and electron spin reso nance￡(r)Conductivity measurement in dicates that the title materials hav e good conductivity￡(r)
