Abstract:
Carbon Quantum Dots (CQDs) have been extensively employed in various fields of science such as
sensing, catalysis, and drug delivery. In this work, ionic liquid coated CQDs (IL@CQDs) have been used as
catalysts for the rearrangement of a 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) amide coupling
intermediate. The rearranged product was confirmed by single crystal structure analysis and it was
processed into organic nanoparticles (ONPs). An optical detection method was used to scrutinize the
anion sensing properties. The ONPs were found to be sensitive and selective for the recognition of highly
toxic cyanide ions through enhancement in the fluorescence intensity. The cyanide ion co-ordinates with
the –NH groups of the product and restricts the rotation of molecules around the single bond. The ONPs
coated over silica-beads were also showing CN− recognition in the solid state. The detection limit for
CN− sensing was found to be 3.8 nM, and real sample analysis depicts more than 90% accuracy in
detection.
