ИСТИНА

Porphyrins are promising compounds for the development of sensors for detection trace amounts of toxic metal cations in aqueous environments. In this work, the effect of the composition and number of receptor groups on the analytical characteristics of ligands for binding of toxic metals cations in aqueous solutions and in organized ultrathin films on liquid and solid substrates was studied.Colorimetric and fluorescent sensors, as well as polymer films selective for copper and lead cations in aqueous solutions based on water-soluble tetrasubstituted porphyrin (L1) were created. Polymer films of porphyrin L1 in a composition with agarose are capable of detecting copper cations in aqueous solutions up to 10–9 M, which are almost 2 decimal orders lower than the MPC of copper cations in drinking water (1.6x10-7 M). Increasing the number of peripheral receptor groups from four to eight (porphyrin L3) allowed one to create a fluorescent sensor for determination of copper cations in aqueous solutions with absolute selectivity. For a monolayer of octa-substituted porphyrin L4 on the surface of deionized water, a reversible switching of the optical characteristics in the “compression-expansion” cycles was detected, which is explained by the change in the film's aggregation state. Nanostructured thin-film sensors on the surface of a liquid or solid substrate for determination of copper cations in aqueous solutions were created based on organized planar systems of porphyrins (L2 and L4).