“…[ 49 ] The results are received on organized or chaotically constructed layers of MPcs, for which a kinetically controllable slow reversal stage (the dissociation of the axial molecule) is marked as the basic problem in the sensor technology. [ 50–52 ] Numerous researches of solid‐state receptors based on MPs predominantly with two charged metal cations, which were reviewed in the chapter, [ 53 ] have allowed receiving such characteristics as a concentration limit of sensitivity, time of response, and service life, but did not yield the new knowledge about the heterocyclic base–MP interaction characteristics and the MPL stability. Obtaining such characteristics in the solutions, [ 54 ] which are described below on an example MPXL as receptors of biologically active bases as imidazole, benzimidazole, pyridine, hydrogen sulfide, and piperidine, have allowed to define a way of the receptor structure optimization and to conduct the direct search in the practical purposes.…”