A highly selective turn-on fluorescent sensor for Cu(ii) based on an NSe2 chelating moiety and its application in living cell imaging†
Abstract
In this study, a boron-dipyrromethene (BODIPY)-based fluorescent chemosensor CBS was developed for metal ion sensing. It was found that CBS containing an NSe2 moiety exhibited high selectivity for Cu2+ detection while CBS in the presence of Cu2+ displayed significant fluorescence enhancement. However, the metal ions Ag+, Ca2+, Co2+, Cr3+, Fe2+, Fe3+, Hg2+, K+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in the fluorescence values of the system. The binding constant (Ka) of Cu2+ binding to CBS was found to be 7.28 × 103 M−1. The binding ratio of CBS–Cu2+ complexes was determined from the Job plot to be 1 : 1. The maximum fluorescence enhancement caused by Cu2+ binding to CBS was observed over the pH range 5.0–9.0. Additionally, the methyl thiazolyl tetrazolium (MTT) assay demonstrated the CBS to have low cytotoxicity.