Synthesis of crab-shell derived CQDs for Cd2+ detection and antibacterial applications

The green synthesis of scalable high-quality fluorescent carbon quantum dots (CQDs) from natural biomass always remains an attraction. CQDs are promising materials for sensing the cadmium ions, as a class of toxic heavy metal ions, and have attracted much attention due to their chronic toxic effects on humans. The CQDs from crab shell waste were synthesized by the one-step hydrothermal method as a pioneering study and evaluated for Cd2+ ions detection and antibacterial activity. The synthesized CQDs exhibited bright green fluorescence under UV light irradiation (330 nm) and showed exorbitant quenching of Cd2+ ions in aqueous media by selective detection at the concentration range of 50–250 µM. They also exhibited antibacterial activity against two water-borne pathogens, E. coli and K. pneumonia indicating the practical applicability of CQDs in Cd2+ ions detection and antibiosis.