A new ICT and CHEF based visible light excitable fluorescent probe easily detects in vivo Zn2+

A new chelator and ICT donor based visible light excitable Zn2+ sensor was designed and developed by integrating quinoline and 2-hydroxy-3-(hydroxymethyl)-5-methylbenzaldehyde. The probe is sensitive towards Zn2+ in absorbance as well as in fluorescence experiments in 90% aqueous medium. The sensor demonstrates Zn2+-specific emission enhancement due to the ICT and CHEF process with the LOD in the range of 10(-8) M. The fluorescence quantum yield of the chemosensor is only 0.02, and it increases almost 11-fold (0.22) after complexation with Zn2+. Interestingly, the introduction of other metal ions causes the fluorescence intensity to remain almost unchanged. Moreover, the ability of the probe (BQ) to sense Zn2+ in living cells has been explored.