Synergistic optical sensing of heavy metal ions using Mesua Ferrea derived carbon dot embedded Alginate based biopolymeric film as a sensor platform

Widespread environmental pollution from heavy metals poses severe health hazards, necessitating advanced detection methods. This study presents an innovative approach utilizing Mesua Ferrea Carbon Dots (MFCDs) incorporated biopolymeric nanocomposite films for optical identification of heavy metal ions (Fe3+, Cd2+, Hg2+, Pb2+, Cu2+). A blend of Na-Alginate and Agarose biopolymer was prepared as a matrix. Hydrothermally synthesized MFCDs possess negative zeta potential with their characteristic photoluminescence property. The MFCDs incorporated Na-Alginate-Agarose biopolymeric nanocomposite (MAA) film displayed enhanced hydrophilicity and UV absorption behaviour, showcasing its potential for optical detection of heavy metal ions. The optical analysis like fluorescence intensity and photoluminescence lifetime studies of the MAA film in response to heavy metal ions were thoroughly studied. The interaction dynamics highlighted specific metal ion quenching capabilities, emphasizing the potential of MFCDs coated film for sensitive heavy metal detection. The quenching mechanism for Fe3+ ions underscored the lowest level of detection in comparison with Cd2+, Hg2+, Pb2+ and Cu2+ ions, contributing to a comprehensive understanding of the optical detection phenomenon. Our research work provides a robust and scientifically validated solid platform for development of economically viable and environmentally benign optical sensor as an alternative of other existing methods for detection of heavy metal ions.