Xylan derived carbon dots composite ZIF-8 and its immobilized carbon fibers membrane for fluorescence selective detection Cu2+ in real samples

Currently, heavy metal such as Cu 2+ contaminants have posed a great threat for ecological security, and the discharge of sewage containing Cu 2+ into water and soil will cause damage to environment and even human health. At present, fluorescent solutions are generally used for Cu 2+ detection, but the they have defects such as easy leakage, difficult storage, poor photostability and inaccurate Cu 2+ detection. Herein, biomass solid-state fluorescence carbon fibers membrane detection platform ( NFE-CDs ) was firstly fabricated by encapsulating xylan carbon dots (CDs) into metal–organic framework ( MOF )( E-CDs @ZIF-8) using in situ growth methods and electrospinning technology. NFE-CDs was ued to improved response site of Cu 2+ by taking advantage of cooperative hybridization and electronic coupling effects. Owning its excellent fluorescence properties, NFE-CDs displayed excellent selectively for Cu 2+ based on ‘turn-on’ fluorescence response, ultra-short fluorescence response time (<1s) and detection limit (3.48 nM) that was well below U.S. EPA safety levels. The practical applications of NFE-CDs also exhibited high specificity for Cu 2+ detection in zebrafish and water samples (school lake, Xuanwu Lake and Yangtze River) with the recovery rates of 97%-112%. The developed fluorescence sensing platform was utilized to predict and detect water quality and safety by monitoring Cu 2+ change. This strategy demonstrates a promising biomass fluorescence platform for Cu 2+ detection for water treatment research and envrionment bioanalytical applications.