Stability of pyrene-1-carboxylic acid and other pyrene derivatives immobilized on silane gels

The aim of the research was also to estimate suitability of the silane gel, which contained a selected immobilized fluorophore, for application in the optical sensor. This criterion includes determination of the kinetics of fluorophore elution from the gel as well as estimation of the interactions of fluorophore immobilized in the gel with microenvironment. Therefore, to carry out this part of the research, the silane gel was formed into a thin layer deposited on a glass surface. Next, the kinetics of elution of pyrene-1-carboxylic acid, 1,3-bis(1-pyrenyl)propane as well as pyrene and aminopyrene from this layers by water and ethanol was investigated. Elution rate constants were determined with the use of the first-order kinetics. Three stages of the elution with different duration were distinguished: I 0-4 min, II 4 min-1 h and III, the slowest one-above 1 h. Stability of the probes immobilized in these gels during storage in water or ethanol for several days was also determined.