A naphthalimide–quinoline based probe for selective, fluorescence ratiometric sensing of trivalent ions

A new naphthalimide–quinoline based probe (NAQ) is designed and synthesized and its structure is confirmed through single crystal analysis. It detects the trivalent ions (Fe3+ or Al3+ or Cr3+) selectively among other alkali and transition metal ions studied. NAQ shows a distinct ratiometric fluorescence behavior upon addition of trivalent metal ions in CH3CN–HEPES buffer solution (40/60, v/v, pH = 7.4). This fluorogenic sensing of NAQ to M3+ (M3+ = Fe3+ or Al3+ or Cr3+) can be observed by the naked eye, when illuminated under the UV light.