Glutathione-capped Syzygium cumini carbon dot-amalgamated agarose hydrogel film for naked-eye detection of heavy metal ions

Abstract Development of a facile and sensitive analytical tool for the detection of heavy metal ions is still a challenging task because of interference from other chemical species. In this work, glutathione (GSH)-capped Syzygium cumini carbon dots (CDs) have been integrated with agarose hydrogel film and used as an amalgamated solid probe for sensing of different metal ions (Pb2+, Fe3+, and Mn2+). The synthesis of a solid sensing platform is based on the electrostatic interactions between GSH-capped Syzygium cumini CDs and agarose hydrogel. The developed hydrogel-based solid probe exhibited good linearities with the concentration ranges of metal ions from 0.005 to 0.075, 0.0075 to 0.1, and 0.0075 to 0.1 mM with detection limits of 1.3, 2.5, and 2.1 μM for Pb2+, Fe3+, and Mn2+ ions, respectively.