Enhanced performances of sensors based on screen printed electrodes modified with nanosized NiO particles

In this paper screen printed electrodes modified with NiO nanoparticles were developed and characterized. NiO nanoparticles were purposely synthesized by a microwave-assisted procedure followed by calcination either at 400 °C or 600 °C and characterized by X-ray diffraction and Scanning Electron Microscopy. Screen printed electrodes were modified by drop casting either set of NiO nanoparticles dispersed in different solvents, i.e. H2O, CH3CN, ethanol and DMF-H2O and characterized by Cyclic Voltammentry using ferrycianide as electroactive probe. All NiO-SPEs show enhanced performances with respect to the bare electrodes. The largest electroactive area, homogeneity, electron kinetic transfer and smallest peak-to-peak separation is displayed by the screen printed electrodes modified with NiO prepared at 400 °C and dispersed in H2O. Thus this electrode was probed for the detection of benzoquinone, epinephrine and norepinephrine, demonstrating an enhancement of the electrochemical activity and a separation of the reduction peaks compared to the bare electrodes.