Rapid and reliable triple-emissive detection of 2,6-dichloro-4-nitroaniline as a pesticide based on a high-nuclear Cd(II)-Sm(III) nanocluster.

A luminescent 56-metal Cd(II)-Sm(III) nanocluster (1, molecular sizes: 4.5 × 2.7 × 2.7 nm) was constructed from a flexible Schiff base ligand, and its crystal structure was determined using the X-ray diffraction method. It shows a rapid triple-emissive response to 2,6-dichloro-4-nitroaniline (DCN, a common pesticide) with high sensitivity and selectivity, which can be used to quantitatively analyze the DCN concentrations in fruit extracts. The limits of detection (LODs) of 1 to DCN for the visible ligand-centered and Sm(III) emissions and NIR Sm(III) luminescence are from 0.95 μM to 2.81 μM.