A novel ratiometric fluorescent probe for sensitive and selective detection of Cu2+ based on Boranil derivatives

1 is the first ratiometric fluorescent probe for Cu2+ based on Boranil derivatives with high sensitivity, excellent selectivity and rapid response time. [Display omitted] •A novel ratiometric fluorescent probe 1 for Cu2+ based on Boranil derivatives was developed for the first time.•The detection limit of 1 for Cu2+ was found to be 0.52 μM.•1 exhibited a rapid response of Cu2+ within 10 min at room temperature.•1 could detect Cu2+ by an obvious fluorescence color change under a 365 nm UV lamp. A novel ratiometric fluorescent probe 1, consisting of Boranil derivative as the fluorophore and picolinate as the recognition site for Cu2+, was designed and synthesized. 1 was found to display ratiometric response while interacting with Cu2+ by undergoing a Cu2+-promoted hydrolysis of the picolinate moiety for the release of its precursor, 2. We observed that 1 not only showed quick response time (within 10 min), high sensitivity (detection limit of 0.52 μM), and high selectivity for Cu2+ over other metal ions, but also allowed us to detect Cu2+ in a convenient way of observing fluorescence color change under a 365 nm UV lamp using naked eyes. Our study introduced the first ratiometric fluorescent probe for Cu2+ based on Boranil derivative.