New magnetic polymeric hybrid composite electrode material for amperometric nitrite sensor.

New modified electrode materials, based on a combination of hybrid nanocomposites such as magnetic nanoparticles, inorganic polymer (SiO2) and different types of organic polymers, were studied. Three types of organic polymers were used in order to find the effect that each of polymers has on the electrochemical properties of the final material. The electrochemical properties of the synthesised materials were investigated, the best electrochemical response was for pAAc covered nanoparticles compared to the other three tested materials. This favourable electrochemical response effect is due to the fact that in case of this material we succeed in obtaining a very uniform coverage of the polymeric shell with a favourable hydrogel structure and thicknesses which is perfectly suitable for adsorption of a relatively high concentration of TB in a very easi and homogenous way. By electrochemical measurements it was proved that this electrode presents electro-catalytic effect towards nitrite oxidation and can be used for nitrite detection. By comparing with other electrodes, the electro-catalytic effect of MNPs-SiO2-pAAc is better because the nitrite oxidation peak appears in this case at a potential closer to 0 mV vs. Ag/AgCl/KClsat, which is favourable to avoid interferences in amperometric nitrite detection in real samples. [ABSTRACT FROM AUTHOR]