Encapsulating Ln3+ in metal-organic framework-bentonite composite for multifunctional colorimetric recognition of DPA and PO43-

The multifunctional sensor for various environmental pollutants based on the hybridization of metal-organic frameworks is a solution with great potential for the development of novel monitoring technologies. In this work, a new composite, namely, Ln3+@[email protected], was synthesized through a feasible hybridizing and post-modification method. Ln3+@[email protected] could perform highly sensitive and selective detection of dipicolinic acid (DPA) (detection limit of 28 nM) and PO43− (detection limit of 34 nM) through different fluorescence signals. Furthermore, an easy-to-prepare test strip investigation demonstrated the great potential of Ln3+@[email protected] in determining DPA and phosphate levels in aquatic environments, thereby demonstrating the advantages of developing multifunctional sensors based on the principle of combination. A semiquantitative visual detection of DPA or PO43− could also be performed easily by using a smartphone to collect the RGB values of the fluorescent probe solution. This approach is time-saving and convenient for the real-time monitoring of DPA or PO43− in water samples.