Carboxymethyl chitosan‒promoted luminescence of lanthanide metallogel and its application in assay of multiple metal ions

In this work, the luminescence of lanthanide supramolecular metallogel formed by the self-assembly of 5,5′,5″-(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)triisophthalate (H 6 L) and Tb 3+ was efficiently promoted by carboxymethyl chitosan (CMCS). The total quantum yield of the resultant metallogel (denoted as H 6 L/Tb 3+ /CMCS gel) was 9 times higher than the gel without CMCS. The average lifetime of H 6 L/Tb 3+ /CMCS gel increased from 0.51 ms to 1.20 ms. More importantly, the aqueous dispersion of H 6 L/Tb 3+ /CMCS xerogels showed a stable and pH-dependent luminescence. Based on the selective affinity of CMCS to different metal ions as well as with the aid of principal component analysis, H 6 L/Tb 3+ /CMCS can be used as a sensor array to distinguish 11 metal ions ( P  < 0.05). This work provides a new strategy for the design and development of bio-based functional luminescent lanthanide supramolecular metallogels.