Single chemosensor for sensing multiple analytes: Selective fluorogenic detection of Cu2+ and Br−

A tripodal receptor R1 with a combination of nitrogen and oxygen-based binding sites was designed and used for the selective determination of Cu2+. The fluorescence emission profile of R1 in the presence of Cu2+ showed a marked enhancement in fluorescence intensity, indicating high selectivity among other metal ions. The R1–Cu2+ complex was further explored as a sensor for anion detection. Upon addition of Br−, switching to a fluorescence “off” state was observed. The Br− selectivity of the complex over a wide range of concentrations was observed via titrimetric analysis through changes in the emission spectra.