Prussian blue (PB) shows high activity and selectivity toward the reduction and oxidation of hydrogen peroxide. It has been extensively studied for the construction of electrochemical sensors and biosensors, in particular for measuring hydrogen peroxide concentration.
PB nanoparticles were immobilized in polyelectrolyte (PE) multilayers using the layer-by-layer method. Graphene oxide (GO) was deposited from its aqueous suspension forming additional layers of the film. Then the multilayers films were exposed to the elevated temperature, 180ºC, to turn graphene oxide into its reduced form (rGO). We compared, using the cyclic voltamperometry, the electroactive and electrocatalytic properties of PE/PB multilayer films with ones containing rGO or conductive polyelectrolytes: poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), polypyrrole and polyaniline .
The incorporation of the conductive polymers enhanced the electroactive properties of PE/PB multilayer films by up to 100%, which could be associated with more effective deposition of PB nanoparticles in films with some conductive polyelectrolytes as well enhancement of electron transfer to the electrode surface. On the other hand the multilayers with the reduced graphene oxide showed up to 40 times higher PB redox current densities than films constructed only with nanoparticles and polycation - poly(allylamine hydrochloride) (PAH). Due to synergistic, electrocatalytic effect for the redox processes of hydrogen peroxide and enhanced conductivity of rGO, the electrodes covered with hybrid (PB/PAH/rGO) films showed high current densities in the micro- to milimolar solutions of H2O2. That indicates on the possibility of the application of those films as effective sensor layers for the electrochemical detection of hydrogen peroxide.
Ackowledgements: The work was supported by the Polish National Science Center, the Marian Smoluchowski Krakow Research Consortium - Leading National Research Centre KNOW and COST Action CM1101
ncpajor@cyf-kr.edu.pl
