Rapid detection of Cu2+ and Cr3+ ions in industrial wastewater using gelatin-poly-ε-caprolactone nanofiber fluorescent sensors

Industrial wastewater, a byproduct of rapid industrialization, often contains hazardous heavy metal ions such as Cu 2+ , Cr 3+ , posing significant risks to environmental and human health. To address the urgent need for fast and simple detection methods in industrial enterprises, we developed gelatin-poly-ε-caprolactone (GEL-PCL) nanofiber fluorescent sensors, incorporating 1,4-dihydroxyanthraquinone (1,4-DHAQ), for the rapid detection of Cu 2+ , Cr 3+ ions. Electrospinning was used to prepare 1,4-DHAQ@GEL-PCL and 1,4-DHAQ/Cu 2+ @GEL-PCL sensors, leveraging the fluorescence intensity fluctuation behavior between 1,4-DHAQ and the target ions to enable fluorescence-based detection. The sensors were characterized using SEM to confirm nanofiber morphology, and UV–Vis spectroscopy to analyze absorption properties. The sensors demonstrated high sensitivity and selectivity for Cu 2+ , Cr 3+ ions, with detection ranges of 4.8–6.5 × 10 −6  M and 2.7–4.3 × 10 −6  M, respectively. Furthermore, they maintained stable performance over 6 months of storage and showed reliable results in actual tannery wastewater samples, comparable to ICP-MS data. This study highlights the potential of these sensors as environmentally friendly, cost-effective tools for monitoring heavy metal ion concentrations, offering significant contributions to sustainable industrial wastewater management, and meeting the pressing needs of enterprises for efficient and straightforward monitoring solutions.