Potentiometric Sensors for Iron(III) Cations Determination

Electrochemical sensors have the ability to convert the electrochemical reaction that occurs be- tween the analyte and the electrode into a useful signal. Potentiometric sensors, ion-selective electrodes, an important member of the electrochemical sensor family, have been the focus of much research for almost a century. Their constant development and combination with the devel- opment of other scientific and technological fields have given them a wide range of applications. Properties of ion-selective electrodes, such as simplicity of method, low cost, small sensor size, fast response, and reliability, have made them valuable competitors of other methods for determining the concentration of analytes in different real samples with minimal or no pretreatment of the samples. Considering the wide distribution and great importance of iron(III) cations in the human body and environment, there is a great need to develop analytical tools for their rapid and effi-cient determination. This paper, presents different literature sources dealing with the development of potentiometric sensors for the determination of iron(III) cations, focusing on scientific papers published in the last decade. The active centre of the sensor, its linear dynamic range, the limit of detection, and the change in potential depending on the change in analyte concentration are shown. It has been found that Fe3+ cations can be determined successfully in numerous real sam- ples, such as pharmaceutical preparations, biological samples, different water samples (drinking, waste, mineral...), food products such as green and black tea, etc. Thanks to the wide linear range, low detection limits, and a wide range of real samples in which they can be applied, ion-selective electrodes are promising candidates for replacing some more sophisticated methods for the deter- mination of iron(III) cations.