Fluoro reactands and dual luminophore referencing: A technique to optically measure amines

An optical sensor for aqueous l-butylamine is presented which combines two novel techniques: A fluorescent indicator dye (fluoro reactand) embedded in a thin polymer layer performs a reversible chemical reaction with the anal yte, causing changes in luminescence intensity. At the same time, inert pho sphorescent beads dispersed within the polymer layer provide luminescence s ignals that act as an internal reference for the indicator dye. As a conseq uence, the optical sensor is independent of light source fluctuations, ambi ent light, drifts in optoelectronic setup, or optical fiber bending.