Rare earth Tb3+ doped PVA/PAA hydrogel for efficient visual detection of Cu2+

Copper (Cu) is an essential micronutrient for the human body. Excessive intake of copper (Cu) can react with human protein and cause a variety of major diseases. In this study, in view of the needs of heavy metal pollution detection, a fluorescent responsive hydrogel based on rare earth doping was designed and developed. The results showed that the introduction of Tb 3+ not only serves as the luminescence center, but also significantly regulates the microscopic morphology, infrared spectroscopy characteristics and swelling properties of PVA/PAA hydrogels. Mechanism studies have shown that Cu 2+ can destroy the coordination structure of PVA/PAA and Tb 3+ , thereby disintegrating the "antenna effect", which ultimately leads to a decrease in the fluorescence intensity of the hydrogel. Based on this, the hydrogel has highly specific fluorescence response characteristics (LOD = 1.38 μM) to heavy metal ions (especially Cu 2+ ), which is expected to provide an efficient and accurate new visual detection method for food quality and safety assessment.