Electrochemical Sensors Based on Track-Etched Membranes for Rare Earth Metal Ions Detection

Electrochemical sensors based on PET track-etched membranes (TeMs) photograft copolymerization of N-vinylformamide (N-VFA) and trimethylolpropane trimethacrylate (TMPTMA). The modification, structure and properties of the modified PET TeMs were thoroughly characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM), thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, gas permeability measurements and contact angle analysis. Parameters affecting the degree of membrane modification were identified and optimized. Moreover, the modified membranes were employed for the detection of Eu3+, Gd3+, La3+, Ce3+ ions using square wave anodic voltammetry (SW-ASV). The sensors exhibited linear detection range from 10-7 M to 10-3 M, with limits of detection of 1.0 × 10-6 M (Eu3+), 6.0 × 10-6 M (Gd3+), 2.0 × 10-4 M (La3+) and 2.5 × 10-5 M (Ce3+). The results demonstrated a significant enhancement in electrochemical response due to the grafted PET TeMs-g-N-PVFA-TMPTMA structure. Furthermore, tests conducted in tap water confirmed that the constructed sensors are suitable for real-world applications, providing reliable accuracy and reproducibility for rare earth element ion detection.