Novel IIPs integrated with a carbon dot-modified GCE sensor for ultra-sensitive and selective detection of uranyl ions
Abstract
Efficient monitoring of uranyl ions has gained considerable attention owing to their involvement in various civilian and military applications. Therefore, a new imprinted sensor with high sensitivity and selectivity was fabricated for the monitoring of uranyl ions in various samples. N-allyl-2-(2-cyanoacetyl)hydrazine-1-carbothioamide was used as a specific chelating agent that strongly interacts with uranyl ions and subsequently polymerizes with ethylene glycol dimethacrylate in the presence of potassium persulfate. The uranyl ions were then leached from the polymeric surface using nitric acid, leaving behind imprinted cavities that enabled the selective recognition of the target ions. The synthesized imprinted polymers were fully characterized using several techniques, including FT-IR, SEM, TEM, AFM, EDX, and elemental mapping. The leached ion-imprinted polymer was deposited onto the surface of the glassy carbon electrode to construct the selective imprinted sensor (IIPs/CDs@GCE), following the deposition of carbon dots to enhance sensitivity. The developed sensor exhibited a wide linear range (1.8 × 10−10–8.6 × 10−3 mol L−1), low limit of detection (5.94 × 10−11 mol L−1), excellent selectivity in the presence of competing ions (imprinting factor = 12.4), and high stability (5 weeks). The imprinted sensor was successfully applied for the detection of uranyl ions in tap water, Nile water, industrial water, soil, and sediment samples, achieving excellent recoveries (97.6–99.8%).