A Turn-on Fluorescent Sensor For Cadmium Ion Detection In Aqueous Solutions

Abstract

Fluorescent sensors have attracted an important interest due to their advantages such as highselectivity, rapid response, easy use, etc. In this study, a rhodamine based fluorescent sensor, RhDP, wassynthesized, and used for selective detection of Cd2+ ions. The sensor responds to Cd2+ via thecoordination induced fluorescence activation (CIFA) mechanism. RhDP gives a very fast and reversiblefluorescence response to Cd2+ in the presence of the metal ions tested. The complex stoichiometrybetween RhDP and Cd2+ was found to be 1:1 and the binding constant was calculated as 2.70 × 107 M-1 inacetonitrile (ACN)/HEPES buffer (10 mM, pH: 7.05, v/v 1:1). The fluorescent detection limit of RhDP forCd2+ was found to be 0.218 µM, which gave a marked sensitivity towards Cd2+.