Electrochemical Sensing and Removal of Cesium from Water Using Prussian Blue Nanoparticle-Modified Screen-Printed Electrodes

Abstract

Selective screening followed by the sensing of cesium radionuclides from contaminated water is a challenging technical issue. In this study, the adsorption functionality of Prussian blue (PB) nanoparticles was utilized for the detection and efficient removal of cesium cations. An efficient PB nanoparticle-modified screen-printed electrode (SPE) in the three-electrode configuration was developed for the electrochemical sensing and removal of Cs+. PB nanoparticles inks were obtained using a facile two-step process that was previously described as suitable for dispensing over freshly prepared screen-printed electrodes. The PB nanoparticle-modified SPE induced a cesium adsorption-dependent chronoamperometric signal based on ion exchange as a function of cesium concentration. This ion exchange, which is reversible and rapid, is associated with electron transfer in the PB nanoparticle-modified SPE. Using this electrochemical adsorption system (EAS) based on chronoamperometry, the maximum adsorption capacity (Qmax) of Cs+ ions in the PB nanoparticle-modified SPE reached up to 325 ± 1 mg·g−1 in a 50 ± 0.5 μM Cs+ solution, with a distribution coefficient (Kd) of 580 ± 5 L·g−1 for Cs+ removal. The cesium concentration-dependent adsorption of PB nanoparticles was also demonstrated by fluorescence spectroscopy based on fluorescence quenching of PB nanoparticles as a function of cesium concentration using a standard fluorophore like fluorescein in a manner analogous to that previously reported for As(III).