A Rhodamine-Based Hg2+ Sensor with High Selectivity and Sensitivity in Aqueous Solution: A NS2-Containing Receptor

Abstract
A rhodamine-based sensor 1 was designed and synthesized by incorporation the rhodamine fluorophore and ionophore NS2 with high affinity to Hg2+. Sensor 1 exhibits a high selectivity and an excellent sensitivity and is a dual-responsive colorimetric and fluorescent Hg2+-specific sensor in aqueous buffer solution. In addition, the 1:1 binding mode was proposed based on the 1H NMR and ES(+)MS studies.