High-sensitive and selective Eu³⁺ electrochemical sensor based on LaB₆ electrode and sodium dodecylbenzene sulfonate

This article reports a simple and low-cost methodology for the determination of europium(III) ion (Eu³⁺) by differential pulse voltammetry (DPV) using a LaB₆ electrode with sodium dodecylbenzene sulfonate (SDBS). The performance of the sensor was initially assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Good linear relationship between the DPV peak current and the concentration of Eu³⁺ is obtained in the range of 10 nM to 2.0 μM. The limit of detection was found to be 6.0 nM (S/N = 3). The proposed sensor is easy to be fabricated and has very good reproducibility, good stability and long life-time in its voltammetric response to Eu³⁺. The mechanism of electrocatalytic oxidation of Eu³⁺ at the LaB₆ electrode containing SDBS is also investigated in detail. Our developed electrochemical sensor provides an attractive alternative choice for the determination of Eu³⁺ in field applications.