Silver nanoparticles-based electrochemical sensing platform for Fe3+ ions in water samples

IGNACIO PEDRE; GONZÁLEZ, GRACIELA ALICIA

Paris

Congreso; ElecNano9; 2020

Societé Chimique de France - International Society of Electrochemistry

Iron is an essential trace metal for living organisms and aqueous environments (1). Most of it comes from the dust present in the atmosphere. However, it has been reported that the melting of Glaciers and ice sheets can be an important source of this element, with concentrations of the order of microM being observed in the southwest coast of Greenland (2). Since it usually is a limiting element, high concentrations of iron in the environmental have been related to algal blooms. For these reasons it is very important to monitor Fe in the aquatic systems (1,3).In the present work, an electrochemical platform for measuring Fe(III) in simulated naturalwater samples is presented (4). The sensor is constructed by immobilization of silvernanoparticles on disposable graphite electrodes obtained by screen printing. When the sensoris dipped in the sample, the immobilized nanoparticles are oxidized by the analyte, givingmeasurable changes in the film, which can be monitored using the technique of electrochemical impedance spectroscopy. The maxima in the impedance spectra (representedas Z´´ vs. frequency) were found to correlate well with the concentration of iron in thesample. The obtained sensors were characterized using SEM microscopy before and after their interaction with a simulated sample.The proof of concept of a sensor for Fe(III) in seawater samples is presented. The concentration range evaluated was from 12 to 50 microM, showing an efficient response forthis type of complex matrix within values typically found in this type of samples. This sensing platform is a cost effective and simple alternative to the traditional methods for measuring metals in environmental samples.