A luminescence endotoxin biosensor prepared by the sol–gel method

Abstract Silicate thin films with terminal amino groups were prepared via the sol–gel technique and selected biological molecules labeled with luminophores were covalently attached to their surfaces. The obtained thin films with covalently bound Concanavalin-A (Con-A) labeled with fluorescein (FITC) were immersed in a buffer and polarized emission spectra were measured. In the next step, the samples were incubated with a lipopolysaccharide (LPS) isolated from Hafnia alvei PCM 1186 bacterial strain and the emission spectra were collected again. The influence of LPS binding to Con-A on the luminescence depolarization has been proven. The system based on the this effect can be employed as an optical sensor for detection of certain types of bacteria.