Benzothiazole-Based Zn²⁺-Specific fluorescent probe and its cell imaging application

A fluorescent probe 2-((2-(benzo[d]thiazol-2-yl)hydrazono)methyl)-5-(diethylamino)phenol (BHP) was designed and synthesized as a Zn²⁺ selective fluorescent chemosensor. It demonstrates Zn²⁺-specific emission enhancement’ while many other ions such as Cd²⁺, Fe²⁺, Ni²⁺, Pb²⁺, Hg²⁺, Al³⁺, Mn²⁺, Ag⁺, Cu²⁺, Co²⁺, Na⁺, K⁺, Mg²⁺ and Ca²⁺, have no response. Notably’ this chemosensor can distinguish Zn²⁺ from Cd²⁺. Its binding stoichiometry with Zn²⁺ is 1 :1 ratio. Its pH-independent Zn²⁺-induced emission enhancement in physiological condition and cell permeability make it an effective intracellular Zn²⁺ imaging agent.