ABSTRACT
For the future development of an optical sensor detecting chloride ions for structural health monitoring, two fluorophores were both evaluated with ratiometric fluorimetry. A chloride-sensitive dye (Lucigenin) and a reference dye (Rhodamine B) were investigated for measuring chloride concentrations. The fluorescence intensity of Lucigenin decreased while the chloride concentration increase due to a collisional quenching process that can be described by the Stern-Volmer relation. The fluorescence intensity of Rhodamine B, meanwhile, only decreased as it degrades over time.
In this work, the response of the fluorescent molecules was tested with different pH, temperatures and chloride ion concentrations. The use of Rhodamine B as a reference dye, coupled with Lucigenin, indicates that the double fluorophore sensor is a promising application for developing an accurate chloride sensor.
