• Amperometric sensor;
  • Silicomolybdate;
  • Cross-linked poly-L-lysine film;
  • Electrocatalysis;
  • Iodate;
  • Periodate


The present work describes reduction of iodate (IO3), and periodate (IO4) at silicomolybdate-doped-glutaraldehyde-cross-linked poly-L-lysine (PLL-GA-SiMo) film coated glassy carbon electrode in 0.1 M H2SO4. In our previous study, we were able to prepare the PLL-GA-SiMo film modified electrode by means of electrostatically trapping SiMo12O404− mediator in the cationic film of PLL-GA, and the voltammetric investigation in pure supporting indicated that the charge transport through the film was fast. Here, the electrocatalytic activity of PLL-GA-SiMo film electrode towards iodate and periodate was tested and subsequently used for analytical determination of these analytes by amperometry. The two electron reduced species of SiMo12O404− anion was responsible for the electrocatalytic reduction of IO3 at PLL-GA-SiMo film electrode while two and six electron reduced species were showed electrocatalytic activity towards IO4 reduction. Under optimized experimental conditions of amperometry, the linear concentration range and sensitivity are 2.5×10−6 to 1.1×10−2 M and 18.47 μA mM−1 for iodate, and 5×10−6 to 1.43×10−4 M and 1014.7 μA mM−1 for periodate, respectively.