Competition‐Free Fluorogenic Detection of Al 3+ by a Chromone‐Naphthalene Conjugate: A Spectroscopic Exploration Supported by DFT Calculations with Cell Imaging

We report a novel probe (12E)‐N′‐((4‐oxo‐4H‐chromen‐3‐yl) methylene)‐2‐naphthohydrazide ( CN ) obtained by the condensation between 3‐formyl chromone and 2‐naphthalene‐carboxyhydrazide. CN can efficiently detect Al 3+ in ethanol: water mixture (ethanol: water =4:6(v/v)) by a sharp increment in emission intensity. Interestingly, the sensing phenomenon is unaffected by any competing cation/anion present in solution alongside Al 3+ . CN is capable of detecting Al 3+ to the lowest limit of ∼10 −8 M. The same shows a 2:1 binding pattern with Al 3+ with an association constant of 6.03×10 4 M −2 . DFT calculations have been performed on CN and CN‐ Al complex. The practical utility of CN has been explored by successful cell imaging of Al 3+ in MDA‐MB 468 cells.