Abstract

This work reports a non-enzymatic amperometric sensor for hydrogen peroxide based on the use of a glassy carbon composite electrode modified with core-shell Cu@PtPd/C nanoparticles. Cu@PtPd/C presents an important electrocatalytic activity towards hydrogen peroxide reduction. The comparison of the sensitivities and the charge transfer resistances for hydrogen peroxide at the glassy carbon composite electrode modified with 5.0% w/w PVC, Pd/C, Pd/C + Pt/C and Cu@PtPd/C demonstrate a clear synergism on the catalytic reduction of hydrogen peroxide at - 0.100 V when having Pt, Pd and Cu incorporated in the core-shell nanostructure. The best compromise between sensitivity, reproducibility and response time was reached with 20.0% w/w Cu@PtPd/C. For the selected sensor (glassy carbon composite electrode containing 20.0% w/w GCPE/Cu@PtPd/C) the analytical parameters are highly competitive compared to similar devices reported in the last years, with a linear relationship between current and hydrogen peroxide concentration between 5.0 x 10(-6) and 2.5 x 10(-4) M, sensitivity of (5.30 +/- 0.09) x 10(5) mu AM(-1) cm(-2) (r(2) = 0.998) and detection limit of (3.7 +/- 0.5) x 10(-7) M. The resulting sensing platform was successfully used for the quantification of hydrogen peroxide in a mouth-wash sample.