Development of a fiber-optic chemical sensor for the detection of cadmium

The detection of cadmium in the environment is very important and in this work the development of an optical fiber chemical sensor for the detection of Cd²⁺ is described. To achieve this, an optical fiber-based technique has been developed using a sensing layer containing a coumarin fluorophore and dipicolylamine receptor. This was covalently attached to the distal end of an optical fiber and exhibited a significant increase in fluorescence intensity in response to Cd²⁺ in the μM concentration range via a photoinduced electron transfer (PET) mechanism. Selectivity for Cd²⁺ over other metal ions has also been demonstrated showing the value of the approach for environmental measurements.