Effect of Nanoparticles on Modified Screen Printed Inhibition Superoxide Dismutase Electrodes for Aluminum

摘要

A novel amperometric biosensor for the determination of Al(III) based on the inhibitionudof the enzyme superoxide dismutase has been developed. The oxidation signal of epinephrineudsubstrate was affected by the presence of Al(III) ions leading to a decrease in its amperometric current.udThe immobilization of the enzyme was performed with glutaraldehyde on screen-printed carbonudelectrodes modifiedwith tetrathiofulvalene (TTF) and different types ofnanoparticles. Nanoparticlesudof gold, platinum, rhodium and palladium were deposited on screen printed carbon electrodesudby means of two electrochemical procedures. Nanoparticles were characterized trough scanningudelectronic microscopy, X-rays fluorescence, and atomic force microscopy. Palladium nanoparticlesudshowed lower atomic force microscopy parameters and higher slope of aluminum calibration curvesudand were selected to perform sensor validation. The developed biosensor has a detection limit ofud2.0 0.2 Mfor Al(III), with a reproducibility of 7.9% (n = 5). Recovery of standard reference materialudspiked to buffer solution was 103.8% with a relative standard deviation of 4.8% (n = 5). Recovery ofudtap water spiked with the standard reference material was 100.5 with a relative standard deviation ofud3.4% (n = 3). The study of interfering ions has also been carried out.