A Colorimetric and Long‐Wavelength “Turn‐On” Fluorescent Probe for Copper Ions Detection with High Selectivity and Sensitivity

In this paper, a seminaphthorhodafluor‐based colorimetric and fluorescent probe with the picolinate moiety as a recognition receptor was designed and simply synthesized by a one‐step reaction. The probe was utilized as a long‐wavelength “turn‐on” fluorescent indicator for Cu 2+ with high selectivity in the aqueous solution. In addition, the color of probe solution changed from nearly colorless to purple in the presence of Cu 2+ , and thus the probe could be used as a colorimetric indicator for Cu 2+ . Furthermore, the linear detection range of Cu 2+ was 0–2 μM and the limit of detection (LOD) for detecting Cu 2+ was calculated to be 52 nM. These results suggest that this probe has high sensitivity toward Cu 2+ . Importantly, this probe has been successfully applied to detect Cu 2+ in real water samples. Also, the probe can image intracellular Cu 2+ through laser confocal fluorescence microscope.