Living cells imaging for copper and hydrogen sulfide by a selective “on–off–on” fluorescent probe

A novel highly selective and sensitive fluorescent probe (NJ1) had been designed and synthesized for Cu2+ detection by fluorescence quenching mechanism, and then the enhancement of fluorescence intensity with the addition of hydrogen sulfide in complex NJ1Cu aqueous solution at physiological conditions were described. This “on–off–on” type fluorescence recognition system was a reversible process, which could be utilized to monitor copper ion and hydrogen sulfide based on a complex NJ1Cu formation–Cu2+ displacement approach. Importantly, this real-time recognition process of Cu2+ and hydrogen sulfide exhibited excellent anti-interference ability. In addition, this new fluorescent probe also has potential utility for Cu2+ and hydrogen sulfide detection in living cells, providing a potential tool for investigating copper ion and hydrogen sulfide in living systems or environment.