Self-assembled 3-aminopropyltrimethoxysilane-phosphomolybdic acid film modified electrode

A composite film modified glassy carbon electrode containing heteropolyanion was fabricated by attaching a Keggin—type heteropolyanion,H3(PMo12O40)·H2O,to a 3-aminopropyltrimethoxysilane(APMS) layer,which was self-assembled on an electrochemically activated glassy carbon electrode through the formation of C—O—Si bond.XPS and cyclic voltammetry were used for the characterization of the composite film.The results showed that PMo12O403-was linked with APMS through the coulombic interaction between PMo12O403-and amine groups of APMS(PMo12O403——APMS),which greatly improved the film stability.The PMo12O403——APMS modified electrode showed three reversible redox pairs of PMo12O403-with a smaller peak-to-peak separation,which was stable in a larger pH range compared with that in the solution phase.The catalytic properties of the modified electrode for those reduction of ClO3-、BrO3-and IO3-were studied.The modified electrode exhibited better electrocatalytic activities for those three anions compared with the PMo12O403-modified glassy carbon electrode.The detection limits were 1.5×10-5,1.0×10-6,5×10-7mol/L for ClO3-,BrO3-and IO3-seperately.