Detection of sodium ion in aqueous soil extract using Prussian blue modified screen-printed electrodes

Different ways to quantify ions in solutions require the pre-treatment of the sample and experimental measurements to be performed. This research proposes to develop an electrochemical method for ions, specifically for sodium ions, using modified surfaces by electrodeposit of Prussian Blue (PB) on carbon (C) and carbon nanotubes (CNT) to get PB-C and PB-CNT. It was observed that the PB-CNTCࣦC modified electrode showed the highest current density compared to the bare carbon (C) and CNTࣦC electrodes, including the modified PB-CࣦC. For this reason, the highest detection and quantification limits were obtained using PB-CNTࣦC with 13.1 and 43.7 µmol L⁻¹, respectively. The different modified and bare electrodes were characterized by electrochemical, spectroscopically, and microscopically methods, where the electronic transference using a probe molecule showed a quasi-reversible behavior in different cases, with the PB presence by cube shape in order of the number of cycles indicating a 3D growth. Additionally, these electrodes were probed for the electrochemical detection of sodium in a synthetic aqueous media. In aqueous samples from soil extracts, these results showed that they are competitive with other analytical methods, such as flame atomic absorption, by the similarity of the sodium concentrations obtained. They look attractive for use in the field of detection of sodium. It is worth noting that this is the first time that this type of surface and electrodes have been used for sodium detection, compared to the existing ones based on the same methodology in the detection of Na⁺ at lower concentrations.